Redirect to the top window on server side

From the server side, redirecting the top window to a new location is generally not possible.

However, we can use Javascript to get the results we want.

Option 1 (using register startup script):

this.ClientScript.RegisterStartupScript(
   this.GetType(), 
   "RedirectTopWindow", 
   "window.open('/PageName.aspx','_top');", 
   true);

Option 2 (using Response.Write):

this.Response.Write("<script>window.open('PageName.aspx','_top');</script>");