Hello everybody, I am developing a small software in C# WPF for a consultancy which does chain system business. I have coded tree structure to show who referred whom. Now it has commission depending on level. If 1 referred 2 & 3 then 1 will get level-1 commission. If 2 referred 4, 5 & 3 referred 6, 7 then 1 will receive level-2 commission. This chain will go on to certain total number. My problem is how I would implement this logic; I am able to calculate who has referred how many members via UDF written for adding TreeViewItem to TreeView. Or tell me how I can count items in treeview in certain level? Node adding UDF:

public void AddNodes(int uid, TreeViewItem tSubNode)
    {
        string query = "select fullname, id from members where refCode=" + uid + ";";
        MySqlCommand cmd = new MySqlCommand(query, db.conn);
        MySqlDataAdapter _DA = new MySqlDataAdapter(cmd);
        DataTable _DT = new DataTable();
        tSubNode.IsExpanded = true;
        _DA.Fill(_DT);

        foreach (DataRow _dr in _DT.Rows)
        {
            TreeViewItem tNode = new TreeViewItem();                
            tNode.Header = _dr["fullname"].ToString()+" ("+_dr["id"].ToString()+")";                
            tSubNode.Items.Add(tNode);

            if (db.HasMembers(Convert.ToInt32(_dr["id"].ToString())))
            {
                AddNodes(Convert.ToInt32(_dr["id"]), tNode);
            }
        }
        //This line tracks who has referred how many members
        Console.WriteLine("Tree node Count : "+tSubNode.Items.Count.ToString()+", UID "+uid);                       
    }

Help me PLEASE!!!!