What am i doing wrong?

[twistedmike]

ok i wanted to make a button to open/close the CD tray i have the code to do it but when i compile it nothing happens could somebody please tell me what i did wrong.

Public Class Form1
    Private Declare Function mciSendString Lib "winmm.dll" Alias "mciSendStringA" (ByVal lpstrCommand As String, ByVal lpstrReturnString As String, ByVal uReturnLength As Long, ByVal hwndCallback As Long) As Long

    Function CDDriveOperation(ByVal Command As String, ByVal hWnd As Long) As String
        Dim Buff As String
        Dim dwR As Long
        Buff = Space$(100) ' Create a buffer
    dwR = mciSendString(Command, ByVal Buff, Len(Buff), hWnd)
        CDDriveOperation = Buff
    End Function

    'Call this Sub to Close the CD Door
    Private Sub CloseCDDoor()
        Dim ret As String
        ret = CDDriveOperation("set cdaudio door closed", 0)
    End Sub

    ' Call this Sub to Open the CD Door
    Private Sub OpenCDDoor()
        Dim ret As String
        ret = CDDriveOperation("set cdaudio door open", 0)
    End Sub

End Class