Adding form elements using checkbox

sounds pretty simple:
I have a checkout form with the user providing his (billing) address.
Then by clicking a checkbox, additional fields should open for providing a shipping address.
I don’t want to have both fieldsets open right from the start but the second toggling when required, since i think it’s an easier checkout process asking the user something like “ship to an other address” than showing a bunch of possibly unnecessary fields.

Long story short, since i have not really a clue of JS, JQuery etc. is there a (more or less) ‘ready-to-go’ script i could use?
I do it in PHP right now but think it might be (again) more userfriendly not to go serverside right away.

Hi there,
Shouldn’t be too difficult. Something like this:

<input type="checkbox" name="mycheckbox" id="mycheckbox" value="0" />
<div id="mycheckboxdiv" style="display:none">
    This content should appear when the checkbox is checked
</div>

<script type="text/javascript">
$('#mycheckbox').change(function() {
    $('#mycheckboxdiv').toggle();
});
</script>

I got this from here: http://stackoverflow.com/questions/7996291/when-checkbox-is-checked-expand-div