using onChange with my PHP script

[wwwfilmfilercom]

Thanks for that - you're right, the first method is more what I'm looking for.

I've done this:

<script type="text/javascript">

document.companyfilter.onchange = function() {
  document.forms['companyfilter'].submit();
};
</script>

And the page refreshes/submits when I change the select menu - but it seems nothing is being 'posted'. I've tested it using the input button to submit and the php code is fine, but the javascript does not seem to post the variable from the form for the php to use.

Any ideas how to fix this?