close window after executing code on server side in Button.Click event

   /Java script
        function CloseWindow() {
            setTimeout(function () {
                GetRadWindow().close();
            }, 0);
        }

        function GetRadWindow() {
            var oWindow = null; if (window.radWindow)
                oWindow = window.radWindow; else if (window.frameElement.radWindow)
                    oWindow = window.frameElement.radWindow; return oWindow;
        }
    /End of Java script

        Protected Sub btnOK_Click(sender As Object, e As EventArgs) Handles btnOK.Click
            'Server side code
             'Close  window
            ScriptManager.RegisterStartupScript(Page, Me.GetType(), "close", "CloseWindow();", True)
        End Sub