We can use the Server.Transfer method to move between pages, however, the URL does not change.  The cross page posting feature in ASP.NET 2.0 allows us to do a normal postback to a different page in the application.  We can then access the values of server controls of the source page in the target page.  Using the cross page posting feature we can also post back to any page and pages in another application.  However, the PreviousPage property will return null if we are posting pages to another application.