PHP function problem

[bhowana]

I have a php function script that is supposed to uncheck a checkbox or checkboxes if a user unchecks it when the preview button is clicked but I can only get the last checkbox that was unchecked to stay unchecked but not the other checkeboxes how can I fix this so that all the checkboxes that where unchecked stay unchecked?Here is part of my PHP function that is giving me the problem.\[code\]if(isset($_POST['preview'])){ foreach($query_cat_id as $qci) { if(!in_array($qci, $cat_id)){ $unchecked = $purifier->purify(strip_tags($qci)); } }}for ($x = 0; $x < count($query_cat_id); $x++){ if(($query_cat_id[$x] == $cat['id']) && ($cat['id'] != $delete_id) && ($cat['id'] != $unchecked)){ echo 'checked="checked"'; }}\[/code\]