Where is the error?

My `select2` box doesn't show results received from `ajax` call, it says - The results could not be loaded.

Here is my code:

HTML:

```
<select class="airportList form-control" name="From_1"> 
 <option disabled selected>Going from</option>
</select>

```

JS:

```
$(function() {
  $(".airportList").select2({
    minimumInputLength: 1,
    // data: [{id:'ADL',text:'Adelaide, Australia, ADL'},{id:'MEL',text:'Melbourne, Australia, MEL'}],
    ajax: {
      type: "GET",
      url: "data.php",
      dataType: 'json',
      delay: 250,
      data: function (params) {
        return {
          q: params.term, // search term
          page: params.page
        };
      },
      processResults: function (data) {
        return {
          results: data
        };
      }
    }
  });
});

```

data.php (that I receive):

```
[
{id:'ADL',text:'Adelaide, Australia, ADL'},
{id:'MEL',text:'Melbourne, Australia, MEL'}
]

```