Android Question Walkie Talkie example - PTT with volume buttons

ub Activity_KeyPress( KeyCode As Int ) As Boolean 'Return True to consume the event
    Dim result, cv, mv, nv, vc As Int
    'vc = ph.VOLUME_ALARM ' Alarms channel
    vc = Starter.ph.VOLUME_MUSIC ' Music channel ===> Beep uses Music channel
    'vc = ph.VOLUME_NOTIFICATION ' Notifications channel
    'vc = ph.VOLUME_RING ' Phone ring channel
    'vc = ph.VOLUME_SYSTEM ' System sounds channel
    'vc = ph.VOLUME_VOICE_CALL ' Voice calls channel
    If KeyCode = 4 Then ' Exit key
        result = Msgbox2( "QUIT?", "MyApp", "YES", "", "NO", Null)
        If result = DialogResponse.POSITIVE Then Return False
    Else If KeyCode = KeyCodes.KEYCODE_VOLUME_UP Then
        mv = Starter.ph.GetMaxVolume( vc )
        cv = Starter.ph.GetVolume( vc )
        nv = cv + 1
        If nv>mv Then nv = mv
        Starter.ph.SetVolume( vc, nv, True )
    else If KeyCode = KeyCodes.KEYCODE_VOLUME_DOWN Then
        mv = Starter.ph.GetMaxVolume( vc )
        cv = Starter.ph.GetVolume( vc )
        nv = cv - 1
        If nv<0 Then nv = 0
        Starter.ph.SetVolume( vc, nv, True )
    End If
    Return True
End Sub ' Activity_KeyPress

Dim ph As Phone ' requires Phone library

Sub Activity_KeyPress (KeyCode As Int) As Boolean 'Return True to consume the event
If KeyCode = KeyCodes.KEYCODE_VOLUME_UP Then
      Log("Up")
                'PTT code
      Return True
   End If
   If KeyCode = KeyCodes.KEYCODE_VOLUME_DOWN Then
      Log("Down")
                'PTT code
      Return True
   End If
End Sub