open window in center js code

   function openWindow(url,width,height)
        {
        window.open(url,"_blank","height="+height+",width="+width+",top="+((screen.availHeight-height)/2)+",left="+((screen.availWidth-width)/2)+",toolbar=no,menubar=yes,scrollbars=yes, resizable=yes,location=no, status=no");
        }