Private Sub TextBox1_Exit(ByVal Cancel As MSForms.ReturnBoolean)
Dim I As Integer
Dim Contenu As String
Contenu = CStr(TextBox1.Value)
For I = 1 To Len(Contenu)
If Mid(Contenu, I, 1) = ":" Then
TextBox1.Value = Left(Contenu, (I - 1)) & ":" & Right(Contenu, (Len(Contenu)) - I)
Exit Sub
End If
Next I
End Sub