[Simon Lloyd]

Ok, go to Plugins & Products in your admincp, Add new plugin, give it a name and description, use hook loaction "forumdisplay_query" add this code

PHP Code:

$frm = array(1,2,3,4,5,6);
if (in_array($forumid, $frm)) { 
$fld = 'prefixid';      
$query= "SELECT DISTINCT $fld FROM ".TABLE_PREFIX."thread";   
$result = mysql_query($query) or die(mysql_error());    
$dropdown = "<form>\r\n<select name='myfld'>";    
while($row = mysql_fetch_assoc($result)) {  
    
$dropdown .= "\r\n<option value='$row[$fld]'>{$row[$fld]}</option>";}$dropdown .= "\r\n</select>\r\n<input type='hidden' name='f' value='$forumid'><input type='submit' value='Filter by Make (only for this page)' />\r\n</form>";  
  }

$vbulletin->input->clean_gpc('r', 'myfld',  TYPE_STR);  
$myfld = $vbulletin->GPC['myfld'];   
if (!empty($myfld))   
{   
$hook_query_where .= " AND thread.{$fld} = '" . $db->escape_string($myfld) . "' ";  
} 


Replace the forumids (i,2,3,...etc) for the forums that you want this to work on, then in your forumdisplay template put this under $navbar

PHP Code:

$dropdown<br />