'Display mark and ask if student is happy with mark.
    Dim iAns As Integer
    iAns = MsgBox("Mark is: " & sLetterGrade & vbNewLine _
        & "Are you happy with this mark?", vbYesNo)
    If iAns = vbYes Then
        sOut = "Good job!"
    Else
        sOut = "Maybe try working a little harder!"
    End If
    MsgBox sOut