Show If url parameter=

[helwo]

I have a form with an initial jump menu that dynamically populates the next two drop down boxes.On selection of the initial menu, the id is passed through the url.

I want one box not to show if the initial option domestic is chosen.
table is category, field name is category and cat_id the values are domestic =1 and commercial =2
[code]
<?php if ($row_cat_id['category'] == "1")
  { ?>
<select name="problems"></select>
   <?php } // Show if recordset empty ?>[/code]