GlideAjax to auto populate User details in catalog item ServiceNow

Client Script

function onChange(control, oldValue, newValue, isLoading) {
   if (newValue == '') {
      return;
   }
    setRequestedForInfo(newValue);
}
function setRequestedForInfo(newValue){
   var ga = new GlideAjax('global.Workingcode_ServiceCatalog');
 ga.addParam('sysparm_name', 'getUserDetails');
 ga.addParam('sysparm_userid', newValue);
   ga.getXMLAnswer(function(answer){
     var user_data = JSON.parse(answer);
     g_form.setValue("u_email", user_data.email);
  g_form.setValue("u_manager", user_data.manager);
  g_form.setValue("rfs_department", user_data.department);
  g_form.setValue("u_phone", user_data.phone);
  g_form.setValue("u_first_name", user_data.first_name);
     });
}

Script Include

getUserDetails: function() {
     var result = {};
     var user_id = this.getParameter('sysparm_userid');
  var gr_user = new GlideRecord("sys_user");
     if(gr_user.get(user_id)){
      result.department = gr_user.department.toString();
   result.manager = gr_user.manager.toString();
   result.email = gr_user.email.toString();
   result.phone = gr_user.phone.toString();
 result.first_name = gr_user.first_name.toString();
     return new JSON().encode(result);
    },