What am i doing wrong?

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.

Code:

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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

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Probably declared it wrong...

Code:

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Option Explicit
' add Microsoft Multimedia Control component

Private Declare Function mciSendString Lib "winmm.dll" Alias "mciSendStringA" _
  (ByVal lpCommandString As String, ByVal lpReturnString As String, _
  ByVal uReturnLength As Long, ByVal hwndCallback As Long) As Long
 
Private Sub Form_Load()
  OpenCDDoor
  CloseCDDoor
End Sub

Public Sub OpenCDDoor()
  Dim retval As Long
  retval = mciSendString("set CDAudio door open", "", 0, 0)
End Sub

Public Sub CloseCDDoor()
  Dim retval As Long
  retval = mciSendString("set CDAudio door closed", "", 0, 0)
End Sub

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EDIT: Command is a reserved word, I think. I don't know what you are passing as command, either

OK, firstly, my default CD ROM / DVD ROM drive is not D:\, it is F:\.

I always have to do this :

Code:

---

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

Dim sDriveLetter As String
Dim sAlias As String


Private Sub Command3_Click()
  sDriveLetter = "F"
  sAlias = "CD" & sDriveLetter
  mciSendString "open " & sDriveLetter & ": type cdaudio alias " & sAlias & " wait", returnstring, 0&, 0&
  mciSendString "set " & sAlias & " door open wait", returnstring, 0&, 0&
  mciSendString "close " & sAlias, returnstring, 0&, 0&
End Sub

Private Sub Command4_Click()
  sDriveLetter = "F"
  sAlias = "CD" & sDriveLetter
  mciSendString "open " & sDriveLetter & ": type cdaudio alias " & sAlias & " wait", returnstring, 0&, 0&
  mciSendString "set " & sAlias & " door closed wait", returnstring, 0&, 0&
  mciSendString "close " & sAlias, returnstring, 0&, 0&
End Sub

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My advice is, substitute sDriveLetter = "F" with sDriveLetter = "D" or whatever your default CD / DVD ROM drive is.

Works like a charm