GET Variable + Javascript No Trim IE

Question

I used the below code to pull a get variable from URL. It works in Chrome and FF but not in IE.

www.example.com/index.php?link=123

In Chrome/FF, the variable first returns "123" but in IE the variable first returns "www.example.com/123"

Any ideas on how to fix the code so that in IE it returns "123"?

function getUrlVars() {
  var map = {};
  var parts = window.location.href.replace(/[?&]+([^=&]+)=([^&]*)/gi, function(m,key,value {
    map[key] = value;
  });
  return map;
}

var first = getUrlVars()["link"];