private void InitTree(TreeNodeCollection Nds)
    {
        DataView dvroles = new DataView();
        TreeNode tmpNd;

        string strRID;
        dvroles.Table = SubjTable;
        dvroles.RowFilter = " PID=ID";
        foreach (DataRowView drvrole in dvroles)
        {
            strRID = drvrole["ID"].ToString();
            tmpNd = new TreeNode();
            tmpNd.Value = drvrole["ID"].ToString();
            tmpNd.Text = drvrole["Name"].ToString();
            Nds.Add(tmpNd);
            AddChildren(tmpNd.ChildNodes, strRID);
        }
    }

private void AddChildren(TreeNodeCollection Nds, string ParentId)
    {
        DataView dvroles = new DataView();
        TreeNode tmpNd;

        string strRID;
        dvroles.Table = SubjTable;
        dvroles.RowFilter = " PID IS NOT NULL AND PID=" + ParentId;
        foreach (DataRowView drvrole in dvroles)
        {
            strRID = drvrole["ID"].ToString();
            tmpNd = new TreeNode();
            tmpNd.Value = drvrole["ID"].ToString();
            tmpNd.Text = drvrole["Name"].ToString();
            Nds.Add(tmpNd);
            AddChildren(tmpNd.ChildNodes, strRID);
        }
    }