XMLHttpRequest of ajax

      val = charset.indexOf(';');
      if (val != -1)
      {
        charset = charset.substring(0, val);
      }
      val = charset.indexOf(',');
      if (val != -1)
      {
        charset = charset.substring(0, val);
      }
      return charset;
    };

    this.abort = function()
    {
      this._aborted = true;
    };

    this.getAllResponseHeaders = function()
    {
      return this.getAllResponseHeader('*');
    };

    this.getAllResponseHeader = function(header)
    {
      var ret = '';
      for (var i = 0; i < this._headers.length; i++)
      {
        if (header == '*' || this._headers[i].h == header)
        {
          ret += this._headers[i].h + ': ' + this._headers[i].v + 'n';
        }
      }
      return ret;
    };

    this.getResponseHeader = function(header)
    {
      var ret = getAllResponseHeader(header);
      var i = ret.indexOf('n');
      if (i != -1)
      {
        ret = ret.substring(0, i);
      }
      return ret;
    };

    this.setRequestHeader = function(header, value)
    {
      this._headers[this._headers.length] = {h:header, v:value};
    };

    this.open = function(method, url, async, user, password)
    {
      this.method = method;
      this.url = url;
      this._async = true;
      this._aborted = false;
      this._headers = [];
      if (arguments.length >= 3)
      {