Private Sub TextBox1_Exit(ByVal Cancel As MSForms.ReturnBoolean)
Dim Cellule As Range
If TextBox1 <> Format(Now, "dd/mm/yy") Then
Set Cellule = Sheets(NomFeuille).Cells(I, 2).Find(CDate(TextBox1))
If Not Cellule Is Nothing Then
MsgBox "Il existe déjà la date " & Cellule.Value & " en ligne " & Cellule.Row
Else
MsgBox "On va travailler en ligne " & I
End If
End If
End Sub