Open radwindow of a UserControl on button click without post

Question

 Hi,
I have a button which on click has to oepn rad window of usercontrol without post back or
Can i display user control's content in radWindow of aspx page from clientSide. I tried this code
        function ShowDetails() {
var oWindow =  $find("ShowDetailsWindow");
         var oWindow = radopen("~/UserControls/usercntrl.ascx", "ShowDetailsWindow");
}


but not working