I want to update a database field when a user presses the Facebook Like button.

A small snippet of my code below. I've simplified it, so plz don't start about the errors/bad practices ;) 

```
<?php
    function updateLike () {
        mysql_query("UPDATE like SET liked = '1'");
    }
?>

<script>
     FB.Event.subscribe('edge.create', function(response) {
         <?php updateLike() ?>
     });
</script>

```

So, that doesn't work. I've read something about making an AJAX call but I couldn't find a good example for my situation.

Who can push me in the right direction?