my tree has an error and do not worl

[cristi08]

I have a tree that is not working to third level....something it wrong with
the $_GET id_subramura1

$display_block.="<li><a href=\"".$_SERVER["PHP_SELF"]."?id_subramura1="
  .$id_subramura1."\">".$Denumire_Subramura1."</a></strong></li>";
          
          }
              
              if (isset($_GET["id_subramura1"])) {
              if($_GET['id_subramura1']==$id_subramura1)
                
                
                $query2 = "SELECT * FROM subramura_2
                        where id_subramura1='".$id_subramura1."'
                        order by Denumire_Subramura2";
                        
             if(isset($query2) && !empty($query2)) {  
                echo"<!--" . $query2. "-->";
                 $result2= mysql_query($query2)
        or die ("invalid query 4: " . mysql_error());}
        
         $display_block .="<ul>";
         
          while ($row=mysql_fetch_array($result2)){
   $Denumire_Subramura2=strtoupper(stripslashes($row['Denumire_Subramura2']));
   $id_subramura2=$row['id_subramura2'];
   
  $display_block.="<li><a href=\"".$_SERVER["PHP_SELF"]."?id_subramura2="
  .$id_subramura2."\">".$Denumire_Subramura2."</a></strong></li>";
          
    
         
          }
          }
         
  }          
               }
         
    
     echo $display_block;}