$sql = "SELECT id, name FROM cat";
$a = mysql_query($sql);
   while ($row = mysql_fetch_assoc($a)) 
	{
   $catid = $row["id"];
   $catname = $row["name"];
   $body_return .= "<ul><li><a href=edit_cat.php?id=$catid><B>$catname</b></a><ul>";
   	
	$sql2 = "SELECT id,name FROM mark WHERE p_id='$catid'";
		$a2 = mysql_query($sql2);
   		while ($row = mysql_fetch_assoc($a2)) 
			{
			
			$markid = $row["id"];
   			$markname = $row["name"];
   			$body_return .= "<li><a href=edit_mark.php?id=$markid>$markname</a></li>"; 
   					
					$sql3 = "SELECT id,name FROM model WHERE  $catid=p_id && '$markid'=m_id";
						$a3 = mysql_query($sql3);
   							while ($row = mysql_fetch_assoc($a3)) 
							{
								$modelid = $row["id"];
   								$modelname = $row["name"];
   								$body_return .= "<li><a href=edit_model.php?id=$modelid>$markid  $modelname</a></li>"; }
					
		
		}

$sql3 = "SELECT id,name FROM model WHERE p_id=".$catid." AND m_id=".$markid;

mysql_query($query) or die(mysql_error());