function doPopups() {
 if (!document.getElementsByTagName) return false;
 var links=document.getElementsByTagName("a");
 for (var i=0; i < links.length; i++) {
  if (links[i].className.match("popup")) {
   links[i].onclick=function() {
    window.open(this.href, "", "width=430,height=450");
    return false;
   }
  }
 }
}
window.onload=doPopups;