text: const AjaxChecker = response => {
  	if (response.status >= 200 && response.status < 300) {
  		return response.text().then (res => {
  			let obj = JSON.parse(res);
  			if (obj.status != 1)
  				return Promise.reject(new Error(response.status + ": " + obj.msg));
  			else return obj;
  		});
  	} else {
  		return Promise.reject(new Error(response.status + ": " + response.statusText));
  	}
  }
  export default AjaxChecker;
  