[jQuery] $.post does not post

[jQuery] $.post does not post


I have been having hard times with $.post lately... It has all come to
a point that I set up as simple tryout as I could think of and it
still doesn't work.
I have a div in a page and that div has a "button" on it and I would
like it to fireup a php-script by clicking that "button" but I just
can't make it happen. At the moment my tryout setup is like this
(These are ripped from JQuery documentation examples.):
$('#bucket .dlButton').click(function() {
    $.post("dl.php", {first_name:"Tarcila",last_name:"Broder"}, function
(returned_data) {
alert(data);
});
});
And php-file is like:
<?php
echo 'Welcome '.$_POST['first_name'].' '.$_POST['last_name'];
?>
But it just doesn't work... I can pop out an alert just fine or load a
page to a div from there, but not to post. And yes, I have tried with
$_REQUEST[]. :)
Does anybody have any idea what could be wrong?
Alex