function ExternalLinks()
{
 if (!document.getElementsByTagName) return;
 var anchors = document.getElementsByTagName("a");
 var forms = document.getElementsByTagName("form");
 for (var i=0; i<anchors.length; i++)
 {
  var anchor = anchors[i];
  if (anchor.getAttribute("rel") == "external")
    anchor.target = "_blank";
 }
  for (var i=0; i<forms.length; i++)
 {
  var form = forms[i];
  if (form.getAttribute("action") == "https://www.paypal.com/cgi-bin/webscr")
    form.target = "_blank";
 }
}

window.onload = ExternalLinks;