I'm making an click event in which I send the `id` of the employee. I can see the value using `console.log()`; the employee id is getting shown, but I keep getting an index :id error.

```html
<input type="button" class="btn btn-primary" value="Appointment Letter" onclick="downloadempappointmentletter('<?php echo $data->employee_id;?>')">

```

```js
function downloadempappointmentletter(id) {
  $.ajax({
    type: 'POST',
    url: "<?php echo base_url(); ?>Admin/Employee/downloadappointmentletter",
    data: { id: id },
    success: function (data) {
      console.log(data);
    }
  });
}

```

```php
public function downloadappointmentletter()
{
  $empid = $_POST['id'];
}

```

I keep getting error:

> 
> undefined index :id
> 
> 
> 

However when I `echo $data->employee_id;` it shows 1 etc. What am I missing?