function popup(url)
    {
        var width  = 900;
         var height = 500;
         var left   = (screen.width  - width)/2;
         var top    = (screen.height - height)/2;
         var params = 'width='+width+', height='+height;
         params += ', top='+top+', left='+left;
         params += ', directories=no';
         params += ', location=no';
         params += ', menubar=no';
         params += ', resizable=no';
         params += ', scrollbars=no';
         params += ', status=no';
         params += ', toolbar=no';
         params += ', address=no';
         newwin=window.open(url+"?url="+window.location.href,'windowname5', params);
         if (window.focus) {newwin.focus()}
         return false;
    }