error Must declare the scalar variable "@Product_ID". แก้ไขไม่ได้เลย ดูโค้ดข้างในนะคะ

Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click
        Try
            Conn.Open()
            Trs = Conn.BeginTransaction(IsolationLevel.ReadCommitted)

            sql = "insert into SaleOrder (Cus_ID,SaleOrder_Date) values (@Cus_ID,@SaleOrder_Date)"
            cmd = New SqlCommand(sql, Conn)
            cmd.Parameters.AddWithValue("Cus_ID", TextBox1.Text)
            cmd.Parameters.AddWithValue("SaleOrder_Date", Label16.Text)
            With cmd
                .Connection = Conn
                .Transaction = Trs
                .CommandType = CommandType.Text
                .CommandText = sql
            End With
            cmd.ExecuteNonQuery()
            Trs.Commit()

            Conn.Close()

            Conn.Open()

            sql = "select max(SaleOrder_ID) as maxID from SaleOrder "
            cmd = New SqlCommand(sql, Conn)
            Reader = cmd.ExecuteReader
            Reader.Read()
            Dim s_id As Integer
            s_id = CInt(Reader("maxID"))
            's_id = s_id + 1

            Conn.Close()

            Conn.Open()
            ' Trs = Conn.BeginTransaction(IsolationLevel.ReadCommitted)

            Dim i As Integer
            For i = 0 To DataGridView1.Rows.Count - 2
                sql = "insert into LotSaleOrder (Product_ID,sale_amount,SaleOrder_ID) " & _
                                                        "values (@Product_ID,@sale_amount,@SaleOrder_ID) "
                cmd = New SqlCommand(sql, Conn)

                cmd.Parameters.AddWithValue("@Product_ID", DataGridView1.Rows(i).Cells(1).Value)
                cmd.Parameters.AddWithValue("@sale_amount", DataGridView1.Rows(i).Cells(3).Value)
                cmd.Parameters.AddWithValue("@SaleOrder_ID", s_id)
                cmd.Parameters.Clear()

                With cmd
                    .Connection = Conn
                    .Transaction = Trs
                    .CommandType = CommandType.Text
                    .CommandText = sql
                End With

                cmd.ExecuteNonQuery()
                Trs.Commit()
            Next

            MessageBox.Show("บันทึกรายการเรียบร้อย")
            Conn.Close()

        Catch ex As Exception
            Trs.Rollback()
            MessageBox.Show("เกิดข้อผิดพลาด")
            Conn.Close()
        End Try

        
    End Sub