Cookie less sessions in asp.net - Part 63

Suggested Videos
Part 60 - Cookies in asp.net
Part 61 - How to Check if cookies are enabled or disabled
Part 62 - Asp.net session state

In this session, we will discuss about cookie less sessions in asp.net. By default sessions use cookies. The session-id is stored as a cookie on the client computer. This session-id, is then, used by the web-server to identify if the request is coming from the same user or a different user.

We will be using the same example used in Part 62, to demonstrate cookieless sessions. Run the application, and navigate to webform1.aspx. I am using google chrome as my default browser for visual studio. To set google chrome as default browser.
1. Right click on WebForm1.aspx in the solution explorer
2. Select Browse with option
3. From the list select Google chrome
4. Click "Set as Default" button
5. Finally click browse.



At this point, webform1.aspx will be opened using google chrome. Fill in the details for Name and Email fields, and click "Go To WebForm2" button. To view the session cookie
1. Right click on the browser, and select "Inspect Element"
2. Click on the "Resources" button
3. Expand cookies in the "Resources"
4. Finally, select localhost
5. You should now see a cookie with ASP.NET_SessionId

Now, let's disable cookies. To disable cookies in chrome
1. Click on the Button, next to the address bar, in the browser and select "Settings"
2. In the "Search Setting" text box, type cookies.
3. In the search results, click "content settings" button under privacy
4. Under "cookies", select "Block sites from setting any data" and click OK.



So, the cookies are disabled now. Run the application, and navigate to WebForm1.aspx. Fill name and email fields and navigate to WebForm2.aspx. Notice that the Name and Email fields are not displayed. This is because, cookies are disabled. When cookies are disabled, the session-id is not sent to the server. So the server has no way to figure out, if the request for WebForm2.aspx has come from the same user. That is the reason why these fields are not displayed on WebForm2.aspx.

Some of the users, does not like websites writing information to their computers. So it is very common for, users to disable cookies. If that is the case, then websites using cookies, to manage sessions may not work as expected. However, to overcome this problem, cookieless sessions can be enabled. To enable cookieless sessions, set cookieless="true" in web.config as shown below.
<sessionState mode="InProc" cookieless="true"></sessionState>

With this change, navigate to WebForm1.aspx, fill in Name and Email fields, and then navigate to WebForm2.aspx, and notice that, the Name and Email, fields are displayed as expected. Notice, that the session-id is now part of the URL. This session-id is sent back and forth between the client and the web server, with every request and response. The web server, uses the session-id from the URL, to identify if the request has come from the same user or a different user.

For cookieless sessions to work correctly, relative URL's must be used in the application, when redirecting users to different webforms. For example, if you are on http://pragimtech.com/WebForm1.aspx and if you want to navigate to WebForm2.aspx, then use
Response.Redirect("~/WebForm2.aspx") - Relative URL
and not
Response.Redirect("http://pragimtech.com/WebFOrm2.aspx") - Absolute URL (or Complete Path)

Asp.net session state - Part 62

Suggested Videos
Part 59 - QueryString in asp.net
Part 60 - Cookies in asp.net
Part 61 - How to Check if cookies are enabled or disabled

Different techniques to send data from one webform to another 
1. Cross Page Postback: Discussed in Part 55 and Part 56
2. Context.Handler object - Discussed in Part 58
3. Query strings - Discussed in Part 59
4. Cookies - Discussed in Part 60 and Part 61
5. Session state - Will be discussed in this session

The following concepts will be discussed in the subsequent sessions
6. Application state

Just like Query strings, Session State variables can also be used to send data from one webform to another. 



Points to remember about session state variables:
1. Session state variables are stored on the web server by default, and are kept for the life time of a session.
2. The default session state mode is InProc. We will discuss about different session state modes in a later video session.
3. The life time of a session is determined by the timeout value in web.config file. The default is 20 minutes. The time-out value can be adjusted according, to your application requirements.
<sessionState mode="InProc" timeout="30"></sessionState>
4. Session state variables are available across all pages, but only for a given single session. Session variables are like single-user global data.
5. It is always a good practice to check, if a session state variable is null before calling any of its methods, such as ToString(). Otherwise, we may run into runtime NullReferenceExceptions.
if (Session["Name"] != null)
{
    lblName.Text = Session["Name"].ToString();    
}
6. Application performance can be improved by disabling session state, if it's not required. Session state can be turned off at the page or application level.

To turn of the session state at the page level, set EnableSessionState="False" in the page directive
<%@ Page Language="C#" EnableSessionState="False" AutoEventWireup="true" CodeBehind="WebForm1.aspx.cs" Inherits="AdoDemo.WebForm1" %>

To turn of the session state at the application level, set SessionState mode=false in web.config file.
<sessionState mode="Off"></sessionState>



WebForm1.aspx HTML source
<div style="font-family: Arial">
<table>
    <tr>
        <td colspan="2">
            <h1>
                This is WebForm1</h1>
        </td>
    </tr>
    <tr>
        <td>
            <b>Name</b>
        </td>
        <td>
            :<asp:TextBox ID="txtName" runat="server">
            </asp:TextBox>
        </td>
    </tr>
    <tr>
        <td>
            <b>Email</b>
        </td>
        <td>
            :<asp:TextBox ID="txtEmail" runat="server">
            </asp:TextBox>
        </td>
    </tr>
    <tr>
        <td colspan="2"> 
            <asp:Button ID="btnSendData" runat="server" 
            Text="Go to WebForm2" onclick="btnSendData_Click" />
        </td>
    </tr>
</table>
</div>

WebForm1.aspx.cs code:
protected void btnSendData_Click(object sender, EventArgs e)
{
    Session["Name"] = txtName.Text;
    Session["Email"] = txtEmail.Text;
    Response.Redirect("WebForm2.aspx");
}

WebForm2.aspx HTML Source:
<div style="font-family: Arial">
<table>
    <tr>
        <td colspan="2">
            <h1>This is WebForm2</h1>
        </td>
    </tr>
    <tr>
        <td>
            <b>Name</b>
        </td>
        <td>
            :<asp:Label ID="lblName" runat="server">
            </asp:Label>
        </td>
    </tr>
    <tr>
        <td>
            <b>Email</b>
        </td>
        <td>
            :<asp:Label ID="lblEmail" runat="server">
            </asp:Label>
        </td>
    </tr>
</table>
</div>

WebForm2.aspx.cs code:
protected void Page_Load(object sender, EventArgs e)
{
    if (Session["Name"] != null)
    {
        lblName.Text = Session["Name"].ToString();    
    }
    if (Session["Email"] != null)
    {
        lblEmail.Text = Session["Email"].ToString();
    }
}

How to Check if cookies are enabled or disabled - Part 61

Suggested Videos
Part 58 - Techniques to send data from one webform to another
Part 59 - QueryString in asp.net
Part 60 - Cookies in asp.net

Different techniques to send data from one webform to another 
1. Cross Page Postback: Discussed in Part 55 and Part 56
2. Context.Handler object - Discussed in Part 58
3. Query strings - Discussed in Part 59
4. Cookies - Discussed in Part 60

The following concepts will be discussed in the subsequent sessions
5. Session state
6. Application state



How to Check if cookies are enabled or disabled in asp.net? This is what we will discuss in this video session. Most of the articles on the internet, states we can use Request.Browser.Cookies property to check, if the cookies are enabled or disabled. This is incorrect.
if (Request.Browser.Cookies)
{
    //Cookies Enabled
}
else
{
    //Cookies Disabled
}

Request.Browser.Cookies property is used to check, if the browser supports cookies. Most mordern browsers, support cookies. Irrespective of whether, the cookies are enabled or disabled, if the browser supports cookies, Request.Browser.Cookies always returns true. So use this property to check if the browser supports cookies and not to check if the cookies are enabled or disabled.
if (Request.Browser.Cookies)
{
    //Broswer supports cookies
}
else
{
    //Broswer does not supports cookies
}



So, the next question is, how do we check, if cookies are enabled or disabled? 
1. Write a Test Cookie
2. Redirect to the same page
3. Read the Test Cookie
4. If Cookies preseent - Cookies are enabled
5. Else - Cookies are disabled.

To disable cookies in Internet Explorer(IE 9)
1. Click on Tools
2. Select Internet Options
3. Click on the Privacy tab
4. Click the Advanced button, under settings
5. Check Override automatics cookie handling check box
6. Select Block radio button under First Party cookies and Third Party Cookie

The above steps disable cookies, only for the internet zone. If you are testing code on your local machine, and to disable cookies for localhost
1. Run the application
2. Press F12, to open developer tools
3. Then Select, Cache - Disable Cookies

WebForm1.aspx HTML source:
<div style="font-family: Arial">
<table>
    <tr>
        <td colspan="2">
            <h1>
                This is WebForm1</h1>
        </td>
    </tr>
    <tr>
        <td>
            <b>Name</b>
        </td>
        <td>
            :<asp:TextBox ID="txtName" runat="server">
            </asp:TextBox>
        </td>
    </tr>
    <tr>
        <td>
            <b>Email</b>
        </td>
        <td>
            :<asp:TextBox ID="txtEmail" runat="server">
            </asp:TextBox>
        </td>
    </tr>
    <tr>
        <td colspan="2"> 
            <asp:Button ID="btnSendData" runat="server" 
            Text="Go to WebForm2" onclick="btnSendData_Click" />
        </td>
    </tr>
    <tr>
        <td colspan="2"> 
            <asp:Label ID="lblMessage" runat="server"
            ForeColor="Red" Font-Bold="true">
            </asp:Label>
        </td>
    </tr>
</table>
</div>

WebForm1.aspx.cs code:
protected void Page_Load(object sender, EventArgs e)
{
    if (!IsPostBack)
    {
        // Check if the browser supports cookies
        if (Request.Browser.Cookies)
        {
            if (Request.QueryString["CheckCookie"] == null)
            {
                // Create the test cookie object
                HttpCookie cookie = new HttpCookie("TestCookie", "1");
                Response.Cookies.Add(cookie);
                // Redirect to the same webform
                Response.Redirect("WebForm1.aspx?CheckCookie=1");
            }
            else
            {
                //Check the existence of the test cookie
                HttpCookie cookie = Request.Cookies["TestCookie"];
                if (cookie == null)
                {
                    lblMessage.Text = "We have detected that, the cookies are disabled on your browser. Please enable cookies.";
                }
            }
        }
        else
        {
            lblMessage.Text = "Browser doesn't support cookies. Please install one of the modern browser's that support cookies.";
        }
    }
}

protected void btnSendData_Click(object sender, EventArgs e)
{
    // Create the cookie object
    HttpCookie cookie = new HttpCookie("UserDetails");
    cookie["Name"] = txtName.Text;
    cookie["Email"] = txtEmail.Text;
    // Cookie will be persisted for 30 days
    //cookie.Expires = DateTime.Now.AddDays(30);
    // Add the cookie to the client machine
    Response.Cookies.Add(cookie);

    Response.Redirect("WebForm2.aspx");
}

WebForm2.aspx HTML Source:
<div style="font-family: Arial">
<table>
    <tr>
        <td colspan="2">
            <h1>This is WebForm2</h1>
        </td>
    </tr>
    <tr>
        <td>
            <b>Name</b>
        </td>
        <td>
            :<asp:Label ID="lblName" runat="server">
            </asp:Label>
        </td>
    </tr>
    <tr>
        <td>
            <b>Email</b>
        </td>
        <td>
            :<asp:Label ID="lblEmail" runat="server">
            </asp:Label>
        </td>
    </tr>
</table>
</div>

WebForm2.aspx.cs Code
protected void Page_Load(object sender, EventArgs e)
{
    HttpCookie cookie = Request.Cookies["UserDetails"];
    if (cookie != null)
    {
        lblName.Text = cookie["Name"];
        lblEmail.Text = cookie["Email"];
    }
}

Cookies in asp.net - Part 60

Suggested Videos
Part 57 - Opening new window using javascript in asp.net
Part 58 - Techniques to send data from one webform to another
Part 59 - QueryString in asp.net

Different techniques to send data from one webform to another 
1. Cross Page Postback: Discussed in Part 55 and Part 56
2. Context.Handler object - Discussed in Part 58
3. Query strings - Discussed in Part 59
4. Cookies - Will be discussed in this session

The following concepts will be discussed in the subsequent sessions
5. Session state
6. Application state



Just like QueryStrings, Cookies can also be used to send data from one webform to another. In general, web sites use cookies to store user preferences or other information that is client-specific. Cookies store small amounts of information on the client’s machine.

Cookies can be broadly classified into 2 types
1. Persistent cookies - Remain on the client computer, even after the browser is closed. You can configure how long the cookies remain using the expires property of the HttpCookie object.
2. Non-Persistent cookies - If you don't set the Expires property, then the cookie is called as a Non-Persistent cookie. Non-Persistent cookies only remain in memory until the browser is closed. 

On WebForm1.aspx, user enters Name and Email. Let's write these values on to the client's computer using cookies. Finally read the values from the cookie and display them in WebForm2.aspx.



WebForm1.aspx HTML source:
<div style="font-family: Arial">
<table>
    <tr>
        <td colspan="2">
            <h1>
                This is WebForm1</h1>
        </td>
    </tr>
    <tr>
        <td>
            <b>Name</b>
        </td>
        <td>
            :<asp:TextBox ID="txtName" runat="server">
            </asp:TextBox>
        </td>
    </tr>
    <tr>
        <td>
            <b>Email</b>
        </td>
        <td>
            :<asp:TextBox ID="txtEmail" runat="server">
            </asp:TextBox>
        </td>
    </tr>
    <tr>
        <td colspan="2"> 
            <asp:Button ID="btnSendData" runat="server" 
            Text="Go to WebForm2" onclick="btnSendData_Click" />
        </td>
    </tr>
</table>
</div>

WebForm1.aspx.cs code:
protected void btnSendData_Click(object sender, EventArgs e)
{
    // Create the cookie object
    HttpCookie cookie = new HttpCookie("UserDetails");
    cookie["Name"] = txtName.Text;
    cookie["Email"] = txtEmail.Text;
    // Cookie will be persisted for 30 days
    cookie.Expires = DateTime.Now.AddDays(30);
    // Add the cookie to the client machine
    Response.Cookies.Add(cookie);

    Response.Redirect("WebForm2.aspx");
}

WebForm2.aspx HTML Source:
<div style="font-family: Arial">
<table>
    <tr>
        <td colspan="2">
            <h1>This is WebForm2</h1>
        </td>
    </tr>
    <tr>
        <td>
            <b>Name</b>
        </td>
        <td>
            :<asp:Label ID="lblName" runat="server">
            </asp:Label>
        </td>
    </tr>
    <tr>
        <td>
            <b>Email</b>
        </td>
        <td>
            :<asp:Label ID="lblEmail" runat="server">
            </asp:Label>
        </td>
    </tr>
</table>
</div>

WebForm2.aspx.cs Code:
protected void Page_Load(object sender, EventArgs e)
{
    HttpCookie cookie = Request.Cookies["UserDetails"];
    if (cookie != null)
    {
        lblName.Text = cookie["Name"];
        lblEmail.Text = cookie["Email"];
    }
}

QueryString in asp.net - Part 59

Suggested Videos
Part 56 - Cross page postback strongly typed reference
Part 57 - Opening new window using javascript in asp.net
Part 58 - Techniques to send data from one webform to another

Different techniques to move data from one webform to another 
1. Cross Page Postback: Discussed in Part 55 and Part 56
2. Context.Handler object - Discussed in Part 58
3. Query strings - Will be discussed in this session.

The following concepts will be discussed in the subsequent sessions
4. Cookies
5. Session state
6. Application state



Points to remember about query strings
1. Querystrings are name/value collection pairs
2. Using querystrings, is a very comman way to send data from one webform to another.
3. Query strings are appended to the page URL.
4. ?(Question Mark), indicates the beginning of a query string and it's value.
5. It is possible to use more than one query string. The first query string is specified using the ?(question mark). Subsequent query strings can be appended to the URL using the &(ampersand) symbol.
6. There is a limit on the Query string length. Hence, Query strings cannot be used to send very long data.
7. Query strings are visible to the user, hence should not be used to send sensitive information, unless encrypted.
8. To read the query string value, use Request object's QueryString property.
9. &(ampersand) is used to concatenate query strings, so if you want to send &, as value for the query string there are 2 ways, as shown below
Using Server.UrlEncode() method
Response.Redirect("WebForm2.aspx?UserName=" + Server.UrlEncode(txtName.Text) + 
    "&UserEmail=" + Server.UrlEncode(txtEmail.Text));

Or
&(ampersand) is encoded as %26, so use, Replace() function to replace & with %26
Response.Redirect("WebForm2.aspx?UserName=" + txtName.Text.Replace("&", "%26") +
    "&UserEmail=" + txtEmail.Text.Replace("&", "%26"));



WebForm1.aspx HTML: We want to send Name and Email, that user enters on WebForm1.aspx to WebForm2.aspx using query strings.
<div style="font-family: Arial">
<table>
    <tr>
        <td colspan="2">
            <h1>
                This is WebForm1</h1>
        </td>
    </tr>
    <tr>
        <td>
            <b>Name</b>
        </td>
        <td>
            :<asp:TextBox ID="txtName" runat="server">
            </asp:TextBox>
        </td>
    </tr>
    <tr>
        <td>
            <b>Email</b>
        </td>
        <td>
            :<asp:TextBox ID="txtEmail" runat="server">
            </asp:TextBox>
        </td>
    </tr>
    <tr>
        <td colspan="2"> 
            <asp:Button ID="btnSendData" runat="server" 
            Text="Go to WebForm2" onclick="btnSendData_Click" />
        </td>
    </tr>
</table>
</div>

WebForm1.aspx.cs
protected void btnSendData_Click(object sender, EventArgs e)
{
    //Using Server.UrlEncode to encode &(ampersand)
    //Response.Redirect("WebForm2.aspx?UserName=" + Server.UrlEncode(txtName.Text) + 
    //    "&UserEmail=" + Server.UrlEncode(txtEmail.Text));
            
    //Using String.Replace() function to replace &(ampersand) with %26 
    Response.Redirect("WebForm2.aspx?UserName=" + txtName.Text.Replace("&", "%26") +
        "&UserEmail=" + txtEmail.Text.Replace("&", "%26"));
}

WebForm2.aspx HTML:
<div style="font-family: Arial">
<table>
    <tr>
        <td colspan="2">
            <h1>This is WebForm2</h1>
        </td>
    </tr>
    <tr>
        <td>
            <b>Name</b>
        </td>
        <td>
            :<asp:Label ID="lblName" runat="server">
            </asp:Label>
        </td>
    </tr>
    <tr>
        <td>
            <b>Email</b>
        </td>
        <td>
            :<asp:Label ID="lblEmail" runat="server">
            </asp:Label>
        </td>
    </tr>
</table>
</div>

WebForm2.aspx.cs Code:
protected void Page_Load(object sender, EventArgs e)
{
    // Read the QueryString values 
    lblName.Text = Request.QueryString["UserName"];
    lblEmail.Text = Request.QueryString["UserEmail"];
}

Techniques to send data from one webform to another in in asp.net - Part 58

Suggested Videos
Part 55 - Cross page postback
Part 56 - Cross page postback strongly typed reference
Part 57 - Opening new window using javascript in asp.net

Different techniques to move data from one webform to another 
1. Cross Page Postback: Discussed in Part 55 and Part 56
2. Context.Handler object - Will be discuss in this video session.

The following concepts will be discussed in the subsequent sessions
3. Query strings 
4. Cookies
5. Session state
6. Application state



In general, the members of one Web form are unavailable from a subsequently displayed Web form. However, when navigating between Web forms using the Transfer or Execute method, data can be retrieve from the previous Web form using Context.Handler object.

Points to remember Context.Handler object
1. Context.Handler returns WebForm1 as the previous page, only the first time when you land on WebForm2 from WebForm1. If there is a button on WebForm2, and if you click the button, the page will postback, and Context.Handler will return WebForm2 instead of WebForm1.
2. For the Context.Handler to return WebForm1 as the previous page, you should have landed on WebForm2, using Server.Transfer or Server.Execute method from WebForm1.
3. The control values from the previous page, can be accessed using FindControl() method or using public properties. The problem with FindControl() method is that, if you mis-spell the ControlID, we could get a runtime NullRefernceException. Using public properties, instead of FindControl() method, can eliminate runtime NullRefernceExceptions.



WebForm1.aspx HTML source:
<div style="font-family: Arial">
<table>
    <tr>
        <td colspan="2">
            <h1>
                This is WebForm1</h1>
        </td>
    </tr>
    <tr>
        <td>
            <b>Name</b>
        </td>
        <td>
            :<asp:TextBox ID="txtName" runat="server">
            </asp:TextBox>
        </td>
    </tr>
    <tr>
        <td>
            <b>Email</b>
        </td>
        <td>
            :<asp:TextBox ID="txtEmail" runat="server">
            </asp:TextBox>
        </td>
    </tr>
    <tr>
        <td colspan="2"> 
            <asp:Button ID="Button1" runat="server" 
            Text="Go to WebForm2" onclick="Button1_Click" />
        </td>
    </tr>
</table>
</div>

WebForm1.aspx.cs Code:
protected void Button1_Click(object sender, EventArgs e)
{
    Server.Transfer("~/WebForm2.aspx");
}

public string Name
{
    get
    {
        return txtName.Text;
    }
}

public string Email
{
    get
    {
        return txtEmail.Text;
    }
}

WebForm2.aspx HTML source:
<div style="font-family: Arial">
<table>
    <tr>
        <td colspan="2">
            <h1>This is WebForm2</h1>
        </td>
    </tr>
    <tr>
        <td>
            <b>Name</b>
        </td>
        <td>
            :<asp:Label ID="lblName" runat="server">
            </asp:Label>
        </td>
    </tr>
    <tr>
        <td>
            <b>Email</b>
        </td>
        <td>
            :<asp:Label ID="lblEmail" runat="server">
            </asp:Label>
        </td>
    </tr>
</table>
</div>

WebForm2.aspx.cs Code:
//On postback Context.Handler returns WebForm2
if (!IsPostBack)
{
    Page lastpage = (Page)Context.Handler;
    if (lastpage is WebForm1)
    {
        //Use FindControl() if public properties does not exist on the 
        //previous page(WebForm1). FindControl() may cause 
        //NullRefernceExceptions due to mis-spelled conrol Id's

        //lblName.Text = ((TextBox)lastpage.FindControl("txtName")).Text;
        //lblEmail.Text = ((TextBox)lastpage.FindControl("txtEmail")).Text;
                    
        //Using public properties can eliminate NullRefernceExceptions 
        lblName.Text = ((WebForm1)lastpage).Name;
        lblEmail.Text = ((WebForm1)lastpage).Email;
    }
}

Opening new window using javascript in asp.net - Part 57

Suggested Videos
Part 54 - Server.execute in asp.net
Part 55 - Cross page postback
Part 56 - Cross page postback strongly typed reference



The following are the different page navigation techniques in asp.net
1. Hyperlink control - Discussed in Part 13 and Part 51 of the ASP.NET video series
2. Response.Redirect - Discussed in Part 52
3. Server.Transfer - Discussed in Part 53
4. Server.Execute - Discussed in Part 54
5. Cross-Page postback - Discussed in Part 55 and Part 56
6. Window.Open 

In this video we will discuss about, opening a new window using javascript method window.open(). First the syntax of the window.open() method.
window.open(URL, name, features, replace)

Parameter Name	Description
URL (Optional)	The URL of the page to open. If URL is not specified, a new window with about:blank is opened.
Name (Optional)	Specifies the target attribute or the name of the window. name - The name of the window _blank - Opens in a new window. Default, if nothing is specified. _self - Opens in the same page _parent - Loaded into the parent frame _top - URL replaces any framesets that may be loaded
Features (optional)	A comma-separated list of items. resizable = yes|no or 0|1 scrollbars = yes|no or 0|1 toolbar = yes|no or 0|1 location = yes|no or 0|1(Specifies whether to display the Navigation Bar. The default is yes) status = yes|no or 0|1 menubar = yes|no or 0|1 left = yes|no or pixels top = yes|no or pixels width = yes|no or pixels height = yes|no or pixels
Replace(Optional)	A boolean parameter that specifies whether the url creates a new entry or replaces the current entry in the window's history list. This parameter only takes effect if the url is loaded into the same window. true - url replaces the current document in the history list. false - url creates a new entry in the history list.

HTML of WebForm1.aspx
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title>Training Demo</title>
    <script type="text/javascript">
        // Javascript function to open the new window
        function OpenNewWindow() 
        {
            var Name = document.getElementById('txtName').value;
            var Email = document.getElementById('txtEmail').value;
            window.open('WebForm2.aspx?Name=' + Name + '&Email=' + Email, '_blank', 'toolbar=no, location=no, resizable=yes, 

width=500px, height=500px', true);
        }
    </script>
</head>
<body>
    <form id="form1" runat="server">
<div style="font-family: Arial">
    <table>
        <tr>
            <td colspan="2">
                <h1>
                    This is WebForm1</h1>
            </td>
        </tr>
        <tr>
            <td>
                <b>Name</b>
            </td>
            <td>
                :<asp:TextBox ID="txtName" runat="server">
                </asp:TextBox>
            </td>
        </tr>
        <tr>
            <td>
                <b>Email</b>
            </td>
            <td>
                :<asp:TextBox ID="txtEmail" runat="server">
                </asp:TextBox>
            </td>
        </tr>
        <tr>
            <td colspan="2">
                <input id="Button1" type="button" value="HTML Input Button - Window.Open" 
                    onclick="OpenNewWindow()" style="width: 300px"
                />
            </td>
        </tr>
        <tr>
            <td colspan="2">
                <asp:Button ID="Button2" runat="server" 
                    Text="ASP.NET Button - Window.Open()" onclick="Button2_Click" 
                    Width="300px" />
            </td>
        </tr>
        </table>
</div>
    </form>
</body>
</html>

Code-Behind code for WebForm1.aspx.cs
protected void Button2_Click(object sender, EventArgs e)
{
    string strJavascript = "<script type='text/javascript'>window.open('WebForm2.aspx?Name=";
    strJavascript += txtName.Text + "&Email=" + txtEmail.Text + "','_blank');</script>";
    Response.Write(strJavascript);
}

HTML of WebForm2.aspx
<div style="font-family: Arial">
    <table>
        <tr>
            <td colspan="2">
                <h1>This is WebForm2</h1>
            </td>
        </tr>
        <tr>
            <td>
                <b>Name</b>
            </td>
            <td>
                :<asp:Label ID="lblName" runat="server">
                </asp:Label>
            </td>
        </tr>
        <tr>
            <td>
                <b>Email</b>
            </td>
            <td>
                :<asp:Label ID="lblEmail" runat="server">
                </asp:Label>
            </td>
        </tr>
        </table>
</div>

Code-Behind code for WebForm2.aspx.cs
protected void Page_Load(object sender, EventArgs e)
{
    lblName.Text = Request.QueryString["Name"];
    lblEmail.Text = Request.QueryString["Email"];
}