public void fillUserType()
        {
            helper.openServer();
            DataTable table_type = new DataTable();
            string sql = "select * from user_type;";
            helper.GetMySqlDataTable(sql, ref table_type);
            userType.DataSource = table_type;
            userType.DisplayMember = "type_name";
            userType.ValueMember = "type_no";
           
        }

        private void userType_SelectedIndexChanged(object sender, EventArgs e)
        {
            if (userType.SelectedIndex > -1)
            {
                DataTable table_name = new DataTable();
                string type_id = userType.ValueMember;
                string sql = "select user_Type.type_table from user_type where user_type.type_no = " + type_id;

//type_id 的值一直是type_no！！！！！！！！

//各路大神为什么呀！！！！！！！！！
                helper.SetUserTypeTable(sql);
            }
            else
            {
                return;
            }
        }