redirecting page issue

I have a one regular aspx page and the another aspx page is has RadWindow.  From the first one, I am opening up Radwindow  aspx page. as a just popup window. Closing Radwindow is no problem with this code below I have on master page.
function Close() {
                var oWindow = GetRadWindow();
                oWindow.argument = null;
                oWindow.close();
            }
 when I use this code below on code behind, it just closes the radwindow and the main aspx page doesnt get refresh at all... Tried several things like Respond.Redirect("mymain.aspx") and Server.Transfer  etc.. What it doesn with those, it redirects to main aspx page in the second aspx page where I have Radwindow .. So, behaving really weird..

Any ideas?
 lblCloseWindow.Text = "<script type='text/javascript'>Close()</" + "script>";