Ajax response Not working in Codeigniter - ajax

Question

I want to show tick.png image on clicking save button when data inserted in database successfully. My view file name is insert_your_committee, model is users_model & controller user
Here is my code of all there files:
My Script of my insert_your_commitee file, All console.log show correct result but success function is not working. What is the problem?
<script>
function save_committee($c_id,$m_id,$start_date){
console.log($c_id);
console.log($m_id);
console.log($start_date);
var mid=$('#irnum'+$start_date).val();
console.log("df"+mid);
var url= "<?php echo site_url("user").'/ref_add';?>";
$.ajax({
url: url,
type: "POST",
dataType:'json',
data: {c_id:$c_id,m_id:$m_id,start_date:$start_date,irnum:mid},
success: function(data){
console.log(data);
$('#'+$start_date).show();
$('#btn'+$start_date).hide();
}
});
}
</script>
My Controller
public function ref_add()
{
$this->load->model('Users_model');
$parms=$this->input->post();
$c_id=$this->input->post('c_id');
$m_id=$this->input->post('m_id');
$s_dateparms=$this->input->post('start_date');
$irnum=$this->input->post('irnum');
$data_to_store = array(
'Cid' =>$c_id,
'Mid' =>$m_id,
'Month' => $s_dateparms,
'Year'=>$s_dateparms,
'Ref_Number' =>$irnum,
);
$params=array();
if ($this->users_model->add_ref($data_to_store)) {
$params['status'] = TRUE;
} else {
$params['status'] = false;
}
$return["json"] = json_encode($params);
echo json_encode($return);
}
And Here is my model
function add_ref($data)
{
$this->db->insert('reference', $data);
$report = array();
$report['error'] = $this->db->_error_number();
$report['message'] = $this->db->_error_message();
if($report !== 0){
return true;
}else{
return false;
}
}

Answer 1

I am not completely sure, but in order to get ajax to work, I had to add return false; after the ajax call in the function.
In my case, I was using ajax for login and backend was in codeigniter.