function externalLinks() { 
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;