Page.ClientScript.RegisterStartupScript(
this.GetType(), "QuickAddPopUpClose", "setTimeout('window.opener.parent.location=window.opener.parent.location + '?t=1';window.close()', 5000);", true);
note that i just add some useless junk on the end to tell the browser that the location has actually changed, so reload the page.... you may want to ensure that the quotes are all in the right places though....