public void create_tree(DataSet ds, int parentid)
{
DataSet newds = new DataSet();
newds= Bpc.GetList(" c_parentid=" + parentid.ToString());
foreach (DataRow dr in newds.Tables[0].Rows)
{
ds.Tables[0].Rows.Add(dr.ItemArray);
create_tree(ds, int.Parse(dr["c_id"].ToString()));
}
}