在程序中如何打開和關閉光驅門

　　API函數聲明如下: 　　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 　　' 調用時的代碼如下 　　Dim Ret As Long 　　Dim RetStr As String 　　'打開光驅門 　　Ret = mciSendString("set CDAudio door open", RetStr, 0, 0) 　　'關閉光驅門 　　Ret = mciSendString("set CDAudio door closed", RetStr, 0, 0)