http://domscripting.com/presentations/xtech2006/

doPopups.js

function doPopups() {
  if (document.getElementsByTagName) {
    var links = document.getElementsByTagName("a");
    for (var i=0; i < links.length; i++) {
      if (links[i].className.match("help")) {
        links[i].onclick = function() {
          window.open(this.getAttribute("href"));
          return false;
        };
      }
    }
  }
}