xmlhttp.open fails when switching from http to an https (SSL) call to a simple perl script

I have the following javascript running using a Win7 IE client that works fine when http is used but not https

<script type="text/javascript">
 function checkloginform() {
   if (window.XMLHttpRequest) {
       xmlhttp=new XMLHttpRequest(); // code for IE7+, Firefox, Chrome, Opera, Safari
   } else {
       xmlhttp=new ActiveXObject("Microsoft.XMLHTTP"); // code for IE6, IE5
   }
   xmlhttp.onreadystatechange=function() {
     if (xmlhttp.readyState==4 && xmlhttp.status==200) {
         var y = xmlhttp.responseText;
         document.getElementById("memo").innerHTML = y;
     } else {
         document.getElementById("memo").innerHTML =
          'Error: '+ xmlhttp.readyState + ' ' + xmlhttp.status;
     }
   }
   xmlhttp.open("GET","/login/login.pl",true);
   xmlhttp.send();
 }
</script>

if I change

xmlhttp.open("GET","/login/login.pl",true);

to

xmlhttp.open("GET","http://ift.tt/1BNurPB",true);

I get nothing back and no status errors?

If I access the url directly from the same browser it does return the expected output.

here is the server side login.pl

#!/usr/bin/perl

MAIN:
{
 print qq~content-type: text/xml\n\TEST\n ~;
 exit;
}