简单ORacle插入数据有关问题，求教！

private string DoInsert(HttpContext context)        {            string result = "";            string name=context.Request.Params["name"];            string parentid = context.Request.Params["parentid"];            if (name != null && parentid != null)            {                OracleConnection conn = new OracleConnection("Data Source=wgyx;user=wgyx;password=wgyx;");                OracleCommand cmd = new OracleCommand("INSERT INTO newclass ( cName, parentid ) VALUES(name,parentid)", conn);                cmd.Parameters.AddWithValue("name", name);                cmd.Parameters.AddWithValue("parentid", int.Parse(parentid));                try                {                    conn.Open();                    cmd.ExecuteNonQuery();                    conn.Close();                    cmd.CommandText = "Select max(id) from newclass";                    cmd.Parameters.Clear();                    conn.Open();                    result = cmd.ExecuteScalar().ToString();                    conn.Close();                }                catch (Exception ex)                {                    result = "-1";                }                finally                {                    conn.Close();                }            }            else            {                result = "-1";            }            return result;        }