Create Nested Namespace from String in JavaScript

gistfile1.txt

function createNamespace(fromString){
  var split = fromString.split('.');
  var parent = window;
  var current = '';
  var length = split.length;

  for(var i = 0; i < length; i++){
      current = split[i];
      parent[current] = parent[current] || {};
      parent = parent[current];
    }

  return parent;
}

//usage: createNamespace("foo.bar.com"); ... returns com for adding items to.