function wxRequest(options, callback) {
  var xhr, timer;
  var timedout = false;

  var abortReq = function () {
    xhr.abort();
    cleanUp();
  };

  var timeoutReq = function () {
    timedout = true;
    xhr.abort();
    cleanUp();
  };

  var ret = {abort: abortReq};

  var cleanUp = function () {
    clearTimeout(timer);
    ret.abort = function () {};
    xhr = undefined;
  };

  if (options.method === 'GET') {
    delete options.headers['Content-Type'];
  } else if (options.json) {
    options.headers.Accept = 'application/json';
    options.headers['Content-Type'] = options.headers['Content-Type'] ||
      'application/json';
    if (options.body &&
        options.processData &&
        typeof options.body !== "string") {
      options.body = JSON.stringify(options.body);
    }
  }

  if (!('body' in options)) {
    options.body = null;
  }
  var dataType = options.binary ? 'arraybuffer' : 'json';
  var responseType = options.body && (options.body instanceof Blob) ? 'arraybuffer' : 'text';
  var headers = {};
  delete options.headers['Referer'];
  for (var key in options.headers) {
    if (options.headers.hasOwnProperty(key)) {
      headers[key] = options.headers[key];
    }
  }

  if (options.timeout > 0) {
    timer = setTimeout(timeoutReq, options.timeout);
  }

  var success = function(ret) {
    if (ret.statusCode >= 200 && ret.statusCode < 300) {
      var data = options.binary ? createBlob([ret.data || ''],{type: ret.header['Content-Type']}) : JSON.stringify(ret.data)
      callback(null,{statusCode: ret.statusCode},data)
    }
    else {
      var err = {};
      if (timedout) {
        err = new Error('ETIMEDOUT');
        err.code = 'ETIMEDOUT';
      } else if (typeof ret === 'object') {
        err = ret
      }
      err.status = ret.statusCode;
      callback(err);
    }
  }

  var fail = function(ret) {
      var err = UNKNOWN_ERROR;
      if (timedout) {
        err = new Error('ETIMEDOUT');
        err.code = 'ETIMEDOUT';
      } else if (typeof ret === 'object') {
        err = ret;
      } else if (typeof ret === 'string') {
        err = new PouchError(500, 'wechat_error', ret);
      }
      callback(err);
  }

  var complete = function() {
    cleanUp()
  }

  if (options.body && (options.body instanceof Blob)) {
    readAsArrayBuffer(options.body, function (arrayBuffer) {
      xhr = wx.request({
          url : options.url,
          data : arrayBuffer,
          header : headers,
          method : options.method,
          dataType : dataType,
          responseType : responseType,
          success : success,
          fail : fail,
          complete : complete
      })
    });
  } else {
    xhr = wx.request({
        url : options.url,
        data : options.body,
        header : headers,
        method : options.method,
        dataType : dataType,
        responseType : responseType,
        success : success,
        fail : fail,
        complete : complete
    })
  }

  return ret;
}