Hello,
I'm using trying to use Ajax under wordpress with jQuery. I have a problem with the response: if the response is null, I can use it, otherwise the javascript doesn't do anything. Someone can help me?

This is the code:
Code:
$('#fromairtosubselect').change(function(){
	var id_suburb = $("#fromairtosubselect").val();
	$.post(
	    ajax_url,
	    {action : 'my_special_action', PickUpID: id_suburb}, 
	    return_function,
	    'json'
	);
});

function return_function(data){
    alert(data);
}
Under Firebug I see the response ( http://d.pr/E4ry ), but the alert starts only if the response is empty.
What is wrong?

Thanks to anyone can help me.