'Declaramos la api messagebox
 
Private Declare Function MessageBox Lib "user32" Alias "MessageBoxA" (ByVal hwnd As Long, ByVal lpText As String, ByVal lpCaption As String, ByVal wType As Long) As Long
 
'Declaramos la constante que desea pal tipo de mensage 
 
 
Const MB_OK = &H0& 'La tipica de ok
 
 
'Para acabar activamos un msg a traves de un boton p.e
 
Private Sub Command1_Click()
MessageBox Me.hwnd, "Aqui_escribes_el_mensaje", App.Title, MB_OK
End Sub
 

Const MB_DEFBUTTON1 = &H0&
Const MB_DEFBUTTON2 = &H100&
Const MB_DEFBUTTON3 = &H200&
Const MB_ICONASTERISK = &H40&
Const MB_ICONEXCLAMATION = &H30&
Const MB_ICONHAND = &H10&
Const MB_ICONINFORMATION = MB_ICONASTERISK
Const MB_ICONQUESTION = &H20&
Const MB_ICONSTOP = MB_ICONHAND
Const MB_OKCANCEL = &H1&
Const MB_YESNO = &H4&
Const MB_YESNOCANCEL = &H3&
Const MB_ABORTRETRYIGNORE = &H2&
Const MB_RETRYCANCEL = &H5&