Lazy loading Google gdata and authorizing the user

<script type="text/javascript" src="http://www.google.com/jsapi"></script>
<script type="text/javascript">
  /**
    Lazy-load Google gdata libraries and check for the user authorization
    @gscope - the google service scope you want to be authorized to, e.g. "http://www.blogger.com/feeds"
    @callback - a function to be called after succesfull authorization
  */
  getGdataAndAuthorize = function(gscope, callback) {
    var checkInterval,
        time = 100,
        verify = function() {
          var loggedIn = !!google.accounts.user.checkLogin(gscope);
          if (loggedIn) {
            callback();
          }else{
            google.accounts.user.login(gscope);
          }
        },
        poll = function() {
          checkInterval = setTimeout(function() {
            if(location.hash.length){
              // the auth token is still in the hash, try one more time
              poll();
            }else{
              // the token was consumed, let's check if auth was succesfull
              verify();
            }
          }, time);
          time = time * 2;
        },
        onGDataLoaded = function() {
          // this needs to be called so gdata consumes the token
          google.gdata.onLoad();
          // in case we're returning from auth page and we have the token in location hash
          if(location.hash.length){
            // start polling for token processing
            poll();
          }else{
            // if it's a simple load, verify if we're logged in
            verify();
          }
        };
    
    // load the gdata libs
    google.load("gdata", "1.x", {
      callback : onGDataLoaded
    });
  };
  
  getGdataAndAuthorize("http://www.blogger.com/feeds", function() {
    alert('gdata loaded and authorized\'re logged in!');
  });
</script>