如何通过ajax jquery显示这位医生的变化时间表

I'm using cakephp 2x. there is a model of doctor and appointment. in appointment controller receptionist can create appointment. When he select a doctor dynamically it will show the doctor's visit_start and visit_end in the appointment form from the doctors table through ajax. But my code is not working ajax function. Please help me to sort out the problem. Thank you

doctors database table

This is admin_add of appointments view.

<div class="appointments form">
<?php echo $this->Form->create('Appointment'); ?>
<fieldset>
    <h2><?php echo __('Create Appointment'); ?></h2>
<?php
    echo $this->Form->input('doctor_id', array(
                            'id' => 'doctor_id',
                            'empty' => '-----Select Doctor-----' ));
?>
<div id="visit">
</div>

<?php

    echo $this->Form->input('patient_id');

    echo $this->Form->input('appointed_time');
?>
</fieldset>
<?php echo $this->Form->end(__('Create')); ?>
</div>
<!-- document javascripts -->    
<script type="text/javascript">
$(document).ready(function () {
    $('#doctor_id').change(function(){
           $doctor_id= $('#doctor_id :selected').val();
            alert($doctor_id);
        $.ajax({
            type: 'POST',
            url:  "<?php echo Router::url(array('controller' => 'doctors', 
'action' =>'get_by_doctor'), true); ?>",
            cache: false,
            data:  doctor_id,
            success: function(data) {
                document.getElementById("#visit").innerHTML = response;
                       },
            error:function (XMLHttpRequest, textStatus, errorThrown) {
                              alert(textStatus);
                       }
        }); 
        return false;
    });
});
</script>
<?php

DoctorsController

public $components = array(
    'Acl',
    'Auth',
    'Session',
    'Security',
    'Cookie',
    'Paginator',
);

public $helpers = array('Html', 'Form', 'Js');

// AJAX
public function admin_get_by_doctor($id=null) {

$doctor_id = $this->request->data['Doctor']['doctor_id'];

$doctor = $this->Doctor->find('first', array(

    'conditions' => array('Doctor.doctor_id' => $doctor_id),

));

$this->set('doctor',$doctor);

$this->layout = 'ajax';

}

ajax view

<dt><?php echo __('Visitting Starts'); ?></dt>
<dd id="visit_start"><?php echo h($doctor['Doctor']['visit_start']); ? 
 >&nbsp;</dd>
<dt><?php echo __('Visitting Ends'); ?></dt>
<dd id="visit_end"><?php echo h($doctor['Doctor']['visit_end']); ?>&nbsp;</dd>

Appointment has been created but the add page did not show the doctors schedule. I want to fix the appointment by knowing the time when doctor visit_start and doctor visit_end.