var asyncRequest = (function() {
  function handleReadyState(o, callback) {
    var poll = window.setInterval(
      function() {
        if (o && o.readyState == 4) {
          window.clearInterval(poll);
          if (callback) {
            callback(o);
          }
        }
      },
      50
    );
  }
  var getXHR = function() {
    var http;
    try {
      http = new XMLHttpRequest;
      getXHR = function() {
        return new XMLHttpRequest;
      };
    }
    catch(e) {
      var msxml = [
        'MSXML2.XMLHTTP.3.0',
        'MSXML2.XMLHTTP',
        'Microsoft.XMLHTTP'
      ];
      for (var i = 0, len = msxml.length; i < len; ++i) {
        try {
          http = new ActiveXObject(msxml[i]);
          getXHR = function() {
            return new ActiveXObject(msxml[i]);
          };
          break;
        }
catch(e) {}
      }
    }
    return http;
  };
  return function(method, uri, callback, postData) {
    var http = getXHR();
    http.open(method, uri, true);
    handleReadyState(http, callback);
    http.send(postData || null);
    return http;
  };
})();

Function.prototype.method = function(name, fn) {
  this.prototype[name] = fn;
  return this;
};

if ( !Array.prototype.forEach ) {
  Array.method('forEach', function(fn, thisObj) {
    var scope = thisObj || window;
    for ( var i = 0, len = this.length; i < len; ++i ) {
      fn.call(scope, this[i], i, this);
    }
  });
}

if ( !Array.prototype.filter ) {
  Array.method('filter', function(fn, thisObj) {
    var scope = thisObj || window;
    var a = [];
    for ( var i = 0, len = this.length; i < len; ++i ) {
      if ( !fn.call(scope, this[i], i, this) ) {
        continue;
      }
      a.push(this[i]);
    }
    return a;
  });
}