function rand(n)
{
  return (Math.floor(Math.random()*n+1));
}
document.write("<div style=\"padding:1px;\"><iframe src=\"http://www.zmap.org/adtest/gt_ad_fr.php?keyword=" + encodeURI(gt_ad_keyword) + "&site=" + gt_ad_site + "&rand=" + rand(10000) + "\" height=\"600\" width=\"160\" border=\"0\" frameborder=\"0\" scrolling=\"no\"></iframe></div>");