May i ask if message box pop out fail message, user can not save data code how to write

i develop a program. the purpose in this program is ,if message box pop out fail message(TextBox_Value_Control) user can not save data to database. hope give me an advise or information.because i am no ideal how can i do.

thank a lot

Private Sub Save_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Save.Click
        If Not cnn.State = ConnectionState.Open Then
            cnn.Open()
        End If
        cmd.Connection = cnn

        If PictureBox1.Image IsNot Nothing Then
            Dim DataPic_Update As Byte() = ImageToBytes(PictureBox1.Image, ImageFormat.Png)
            cmd.CommandText = "insert into Table1(Picture, F1, F2, F3)" &
                            "values (@picture, @F1, @F2, @F3)"

            cmd.Parameters.AddWithValue("@picture", DataPic_Update)
        Else
            cmd.CommandText = "insert into Table1(F1, F2, F3)" &
                            "values (@F1, @F2, @F3)"
        End If

        cmd.Parameters.AddWithValue("@F1", Me.TextBox1.Text)
        cmd.Parameters.AddWithValue("@F2", Me.TextBox2.Text)
        cmd.Parameters.AddWithValue("@F3", Me.TextBox3.Text)

        TextBox_Value_Control()


        cmd.ExecuteNonQuery()
        RefreshData()
        MessageBox.Show("Record Is Added")

        Me.Hide()
        Dim frm = New Form5
        frm.Show()
    
    End Sub

 Private Sub TextBox_Value_Control()
        Dim a As Integer
        a = CInt((Total.Text))

        If CSng(Total.Text) = a Then
            MessageBox.Show("PASS")
        Else
            MessageBox.Show("FAIL")
            sg1.Text = ""
            sg2.Text = ""
            sg3.Text = ""
            sg4.Text = ""
            sg5.Text = ""
            sg6.Text = ""
            sg7.Text = ""
            sg8.Text = ""
        End If
    End Sub