function addLoadEvent(func) {
  var oldonload = window.onload;
  if (typeof window.onload != 'function') {
    window.onload = func;
  } else {
    window.onload = function() {
      oldonload();
      func();
    }
  }
}
function popUp(url) {
	window.open(url)
}
var linkHandlers = function() {
	if (!document.getElementsByTagName) return false;
	var lnks = document.getElementsByTagName("a");
	for (var i=0; i<lnks.length; i++) {
		if (lnks[i].getAttribute("rel") == "external") {
			lnks[i].onclick = function() {
				popUp(this.getAttribute("href"));
				return false;
			}
		}
	}
}
addLoadEvent(linkHandlers);