loadJSONDoc()

  function demo_async() {
    var url = 'META.json';
    var d = loadJSONDoc(url);
    var gotData = function (data) {
      alert('MochiKit.Async version is ' + MochiKit.Async.VERSION);
    };
    var dataFetchFailed = function (err) {
      alert("The data could not be fetched");
    };
    d.addCallbacks(gotData, dataFetchFailed);
  }

どういうトリガでリクエストが飛んでいるんだろう？