[jQuery] onChange event and ptTimeSelect

[jQuery] onChange event and ptTimeSelect


I'm fairly new to jQuery and javascript - I'm also sure I'm missing a
simple concept here but, I can't seem to be able to google myself an
answer.
Situation:
I am using the ptTimeSelect plugin http://pttimeselect.sourceforge.net/example/index.html.
Code-Snippet:
<script src="/jquery.js" type="text/javascript"
language="JavaScript"></script>
<script src="/dimensions.js" type="text/javascript"
language="JavaScript"></script>
<script src="/jquery.ptTimeSelect.js" type="text/javascript"
language="JavaScript"></script>
<script type="text/javascript">
$(document).ready(function(){
$("input[@class=time_select]").ptTimeSelect();
});
$(document).ready(function(){
$("input[@class=time_select]").change( function() {
alert("SpooN");
});
});
</script>
Question:
The onChange handler fires if I manually edit the input field in
question. But the onChange handler doesn't fire if the ptTimeSelect
modifies the field. What do I need to do to get my function to fire
when the ptTimeSelect modifies a field?
Christian