I'm wondering how I can get a JSON format to an array or something usable for me.

I've got the following;

The index.php contains;

1. {"playlist":[{"media_id":"9470","filename":"NEW_4.jpg"}]}

The code:

1. var playlist_array = new Array();
3. function update()
4. {
5.     $.get('index.php', {extension:'screen'},
6.     function(data)
7.     {    
8.         playlist_array = data['playlist'];
9.     }, "json");
10. }
11. function hello()
12. {
13. alert(playlist_array[0]['filename']);
14. }
15. update();
16. hello();

playlist_array[0]['filename'] always is undefined :(
Where 0 can be different integers because the array will be bigger.

Does anyone has an idea how to do this?