<script type="text/javascript">
   $(document).ready(function() {
	$("#trigger").selectOptions("1");
	$("#target").ajaxAddOption("catalog/category_JSON.php?location="+$("#trigger").val(), null, true);
	$("#target").selectOptions("3");
   });
</script>

<select id="trigger"
   onchange="	$(\'#target\').removeOption(/./);
		$(\'#target\').ajaxAddOption(\'catalog/category_JSON.php?location=\'+$(\'#trigger\').val(), null, false);" >
	<option id="0">-- Choose Location: --</option>
	<option value="1">Charleston</option>
	<option value="2">Greenville</option>
</select>

<select id="target" name="status"></select>