use java script or script manager to open the new page
javascript:q=(document.location.href);void(open('http://example.com/submit.php?url='+escape(q),'_self','resizable,location,menubar,toolbar,scrollbars,status'));"
<pre lang="cs">protected override void CreateChildControls()
{
if (ScriptManager.GetCurrent(Page) == null)
{
ScriptManager sMgr = new ScriptManager();
Page.Form.Controls.AddAt(0, sMgr);
}
}