How to: Post ASP.NET Web Pages to a Different Page
By default, controls on ASP.NET Web pages that cause a postback, such as the Button control, post back to the page for processing. However, you can configure controls to post to a different page. For example, you might be creating a multi-page form that collects different information on each page.
On the target page, you can read the values of controls or public properties from the source page. For more information, see Cross-Page Posting in ASP.NET Web Pages.
To post an ASP.NET Web page to another page
Set the PostBackUrl property for the control to the URL of the page to which you want to post the ASP.NET Web page.
The following code example illustrates a Button control that is configured to post to a page named TargetPage in the root of the Web site.
<asp:Button ID="Button1" PostBackUrl="~/TargetPage.aspx" runat="server" Text="Submit" />
For more information, see How to: Pass Values Between ASP.NET Web Pages.