Private Sub TextBox1_Exit(ByVal Cancel As MSForms.ReturnBoolean)
If Len(TextBox1) < 5 Then GoTo message
If Not IsNumeric(Mid(TextBox1.Value, 1, 4)) Or IsNumeric(Mid(TextBox1.Value, 5)) Then GoTo message
Exit Sub
message: MsgBox "saisie incorrecte..."
Cancel = True
End Sub