layui自定义验证,用ajax查询后台是否有重复数据

form.verify({
  aount: function(value, item){ //value表单的值、item表单的DOM对象
  if(value.trim() == ""){
   return '账号不能为空';
  }
  var param = {
 employeeId: $("#hidEmployeeId").val(),
 employeeAount: $("#employeeAount").val()
 }
 var checkResult = "";
 
 $.ajax({
 url: "../../selectEmpIdByAount",
 type: "GET",
 data: param,
 async: false,
 suess: function(result) {
  if(result.extend.isRepeat){
   checkResult = "该账号已存在";
  }
 },
 error: function() {
 }
 });
 return checkResult;
  }
 });