function VideoPreviewPopUp(url){
        var a="toolbar=no,location=no,directories=no,menubar=no,scrollbars=no,resizable=yes,width=600,height=520";
        if (navigator.appName.indexOf("Microsoft")>=0) a+=",left=50,top=50";
        else a+=",screenX=50,screenY=50";
        if( floater != null )
                if( floater.closed == false )
                        floater.close();
                        var floater = null;
        floater=window.open(url,"videopreview",a);
        floater.focus();
}