function aaPopups() {
  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);
        return false;
      }
    }
  }
}

function addLoadEvent(func) {
    var oldonload = window.onload;
    if (typeof window.onload != 'function') {
        window.onload = func;
    } else {
        window.onload = function() {
            if (oldonload) {
                oldonload();
            }
            func();
        }
    }
}

addLoadEvent(aaPopups);