我怎么能把这个代码放在一个按钮中我已经尝试了我所知道的一切
  Private Function NewAward(Mark As Double) As String
Select Case Mark
    Case 90 To 100
        Return "High Distinction"
    Case 75 To 89
        Return "Distinction"
    Case 60 To 74
        Return "Credit"
    Case 50 To 59
        Return "Pass"
    Case Else
        Return "Participation"
End Select
End Function