str = "select 数量 from salesorderdetails where 订单编号='" & ComboBox2.Text.Trim & " '"
            sqlcon.Open()
            sqlcmd.Connection = sqlcon
             = str
            sl = sqlcmd.ExecuteNonQuery().ToString.Trim

终于搞定了,调试完成,而且尽管你们一个字不说.
我......解脱了!哈哈
话说回来,你们...高手们,不厚道,不能因为问题太小而不回答么,不象前辈!!!