Private Declare Function midiOutOpen Lib "winmm.dll" (ByVal lphMidiOut As _
      Long, ByVal uDeviceID As Long, ByVal dwCallback As Long, ByVal dwInstance _
      As Long, ByVal dwFlags As Long) As Long
 
 
    Private Sub OK_Click(ByVal sender As System.Object, ByVal e As _
      System.EventArgs) Handles OK.Click
        Dim PortID As Long = 3
        Dim Midihandle As Long  
        Dim ret = midiOutOpen(Midihandle, PortID, 0, 0, 0)
    End Sub
End Class