function externalLinks() {
 if (!document.getElementsByTagName) return;
 var anchors = document.getElementsByTagName("a");
 for (var i=0; i<anchors.length; i++) {
   var anchor = anchors[i];
   if (anchor.getAttribute("href") &&
       anchor.getAttribute("rel") == "external")
     anchor.target = "_blank";
 }
var forms = document.getElementsByTagName("form");
for(var i = 0; i < forms.length; i++)
 {
   var form = forms[i];
   if(form.getAttribute("action").substring(0, 4) == "http")
   {
      form.target = "_blank";
   }
 }
}
window.onload = externalLinks;