Changing the class and id of a menu with theme overrides

I feel like I've tried everything, and I still I am not having any luck at getting the classes and id's of my ul's to change.

The following code from template.php worked on a 4.7 site I developed a few months ago, but no matter what, I can't seem to get it to work in Drupal 5.

<?php
/********************************************/
function phptemplate_menu_tree($pid = 1) {
  if ($tree = menu_tree($pid)) {
	$output .= "<ul id=\"udm\" class=\"udm\">";
	$output .= $tree;
	$output .= "</ul>\n";
	return $output;
  }
}
/********************************************/
function phptemplate_menu_item($mid, $children = '', $leaf = TRUE) {
  $children = str_replace("<ul id=\"udm\" class=\"udm\">","<ul>",$children);
  return "\t<li id=\"item_".$mid."\">". menu_item_link($mid) . $children ."</li>\n";
  
}
?>

If I remove the menu_item function the class and id's are applied to all the children ul's but still not to the parent list.

I need to have these specific classes for my drop down menus to work properly.

I realize this is a kind of hacked together solution using str_replace, any ideas to make it cleaner?

Any help would be greatly appreciated!