<?php
class Menu {

  function printfield($Active, $Level, $Value, $Link) {
    [...]
  }

  function printchilds($Parents, $Active=0, $Level=0, $Parent=0) {
    $name=$this->that_class;
    $q = new $name;

    $q->query('select ID,Expand,Value,Link from ' . $this->table . ' where GID=' . $Parent . ' and En=1 order by Sort');

    while($q->next_record()) {
      $ID=$q->f(0);
      $Expand=intval($q->f(1));
      $Value=htmlentities($q->f(2));
      $Link=$q->f(3);

      $this->printfield($Active==$ID, $Level, $Value, $Link);

      if (!$Expand) {
        if ($ID==$Active)
          $Expand=true;
        else
          for ($i=0;isset($Parents[$i]);++$i)
            $Expand=$Expand || ($Parents[$i]==$ID);
      }
      if ($Expand)
        $this->printchilds($Parents, $Active, $Level+1, $ID);        # Recoursive call
    }
  }
}
?>

$Parent variable assumes other variables values instead $ID value