VB.NET บันทึกลงฐานข้อมูลแล้ว error ปุ่ม Radio button ต้องแก้ไขอย่างไรบ้าง

Private Sub bttSave_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles bttSave.Click

        If Me.txtName.Text = "" Then
            MessageBox.Show("กรุณากรอกชื่อน้ำยา")
            Me.txtName.Focus()
            Exit Sub
        End If

        
        Dim a As String
        If flagAction = "add" Then
            a = "Insert into product( productID, productName,Item,heavy,price)"
            a &= " Values(@productId,@productname,@Item,@Heavy,@Price)"
        ElseIf flagAction = "edit" Then
            a = "update product set productname ='" & Trim(txtName.Text) & "',item='" & Trim(R1.Checked Or R2.Checked Or R3.Checked Or R4.Checked Or R5.Checked) & "',Heavy='" & Trim(R6.Checked Or R7.Checked Or R8.Checked Or R9.Checked Or R10.Checked Or R11.Checked) & "',price='" & Trim(Txtprice.Text) & "'where productid= '" & Trim(txtId.Text) & "'"
        End If


        With cn
            If .State = ConnectionState.Open Then .Close()
            .ConnectionString = conStr
            .Open()
        End With

        Dim cm As New SqlCommand
        With cm
            .CommandType = CommandType.Text
            .CommandText = a
            .Connection = cn
            .Parameters.Clear()
            If flagAction = "add" Then
                .Parameters.Add("@productID", SqlDbType.NVarChar, 10).Value = Me.txtId.Text
                .Parameters.Add("@productname", SqlDbType.NVarChar, 100).Value = Me.txtName.Text
                If R1.Checked = True Then
                    .Parameters.Add("@Item", SqlDbType.NVarChar, 100).Value = "เงิน"
                ElseIf R2.Checked = True Then
                    .Parameters.Add("@Item", SqlDbType.NVarChar, 100).Value = "โรเดียม"
                ElseIf R3.Checked = True Then
                    .Parameters.Add("@Item", SqlDbType.NVarChar, 100).Value = "นิกเกิล"
                ElseIf R4.Checked = True Then
                    .Parameters.Add("@item", SqlDbType.NVarChar, 100).Value = "ทองคำ"
                ElseIf R5.Checked = True Then
                    .Parameters.Add("@item", SqlDbType.NVarChar, 100).Value = "ทองคำขาว"
                End If

                If R6.Checked = True Then
                    .Parameters.Add("@heavy", SqlDbType.NVarChar, 10).Value = "1"
                ElseIf R7.Checked = True Then
                    .Parameters.Add("@heavy", SqlDbType.NVarChar, 10).Value = "2"
                ElseIf R8.Checked = True Then
                    .Parameters.Add("@heavy", SqlDbType.NVarChar, 10).Value = "3"
                ElseIf R9.Checked = True Then
                    .Parameters.Add("@heavy", SqlDbType.NVarChar, 10).Value = "4"
                ElseIf R10.Checked = True Then
                    .Parameters.Add("@heavy", SqlDbType.NVarChar, 10).Value = "5"
                ElseIf R11.Checked = True Then
                    .Parameters.Add("@heavy", SqlDbType.NVarChar, 10).Value = "10"
                End If
                .Parameters.Add("@price", SqlDbType.Float).Value = Me.Txtprice.Text



            ElseIf flagAction = "edit" Then
                .Parameters.Add("@productID", SqlDbType.NVarChar, 10).Value = Me.txtId.Text
                .Parameters.Add("@productname", SqlDbType.NVarChar, 100).Value = Me.txtName.Text
                If R1.Checked = True Then
                    .Parameters.Add("@item", SqlDbType.NVarChar, 100).Value = "เงิน"
                ElseIf R2.Checked = True Then
                    .Parameters.Add("@item", SqlDbType.NVarChar, 100).Value = "โรเดียม"
                ElseIf R3.Checked = True Then
                    .Parameters.Add("@item", SqlDbType.NVarChar, 100).Value = "นิกเกิล"
                ElseIf R4.Checked = True Then
                    .Parameters.Add("@item", SqlDbType.NVarChar, 100).Value = "ทองคำ"
                ElseIf R5.Checked = True Then
                    .Parameters.Add("@item", SqlDbType.NVarChar, 100).Value = "ทองคำขาว"
                End If

                If R6.Checked = True Then
                    .Parameters.Add("@heavy", SqlDbType.NVarChar, 10).Value = "1"
                ElseIf R7.Checked = True Then
                    .Parameters.Add("@heavy", SqlDbType.NVarChar, 10).Value = "2"
                ElseIf R8.Checked = True Then
                    .Parameters.Add("@heavy", SqlDbType.NVarChar, 10).Value = "3"
                ElseIf R9.Checked = True Then
                    .Parameters.Add("@heavy", SqlDbType.NVarChar, 10).Value = "4"
                ElseIf R10.Checked = True Then
                    .Parameters.Add("@heavy", SqlDbType.NVarChar, 10).Value = "5"
                ElseIf R11.Checked = True Then
                    .Parameters.Add("@heavy", SqlDbType.NVarChar, 10).Value = "10"
                End If

                .Parameters.Add("@price", SqlDbType.Float).Value = Me.Txtprice.Text
            End If
            .ExecuteNonQuery()

        End With
        MessageBox.Show("บันทึกเรียบร้อยแล้ว")
        ShowData()
        DataGridView1.Enabled = False
        Clear()
        bttAdd.Enabled = True
        bttEdit.Enabled = True
        bttClear.Enabled = True
    End Sub