Private Sub CommandButton1_Click()
Dim cible As Long, valtrouve As Integer
If IsDate(Me.TextBox1) Then
cible = CDate(Me.TextBox1)
tmp = Application.VLookup(cible, Range("A4:B" & [a65000].End(xlUp).Row), 2, 0)
If Not IsError(tmp) Then
MsgBox tmp & " est la valeur trouvée!"
Else
MsgBox "inconnu"
End If
End If
End Sub