Ou est mon erreur sur la varible DateDebut ??

What:=CDate(DateDebut)

Dim Message As String, Title As String, Default As String, DateDebut As String
Dim r As Range

Message = "Entrez la date du début de mise à jour a faire"
Title = "Mise à Jour date de début"
Default = "17/05/12"
DateDebut = InputBox(Message, Title, Default)
'...etc....puis je dois faire
Set r = Selection.Find(What:=DateDebut, After:=ActiveCell, LookIn:=xlValues, LookAt:=xlWhole)
If Not r Is Nothing Then r.Select

Sub test()
Dim S As String, N As Long, D As Date
   D = "01/05/2011"
   D = "jj/mm/aaaa"
End Sub

Selection.Find(What:=DateDebut, After:=ActiveCell, LookIn:=xlValues, _
LookAt:=xlPart, SearchOrder:=xlByColumns, SearchDirection:=xlNext, _
MatchCase:=False, SearchFormat:=False).Activate

Dim Message As String, Title As String, Default As String, DateDebut As String
Dim r As RangeMessage = "Entrez la date du début de mise à jour a faire"
Title = "Mise à Jour date de début"
Default = "17/05/12"
DateDebut = InputBox(Message, Title, Default)
'...etc....puis je dois faire
Set r = Selection.Find(What:=DateDebut, After:=ActiveCell, LookIn:=xlValues, LookAt:=xlWhole)
If Not r Is Nothing Then r.Select

Dim Message As String, Title As String, Default As String, a As String, DateDebut As Date
Dim r As Range
Message = "Entrez la date du début de mise à jour a faire"
Title = "Mise à Jour date de début"
Default = "17/05/12"
a = InputBox(Message, Title, Default)
DateDebut = CDate(a)
'...etc....puis je dois faire
Set r = Selection.Find(What:=DateDebut, After:=ActiveCell, LookIn:=xlFormulas, LookAt:=xlWhole)
If Not r Is Nothing Then r.Select

Sub FindDate()
Dim strdate As String
Dim rCell As Range
Dim lReply As Long

    strdate = Application.InputBox(Prompt:="Enter a Date to Locate on This Worksheet", _
                Title:="DATE FIND", Default:=Format(Date, "Short Date"), Type:=1)

    'Cancelled
    If strdate = "False" Then Exit Sub

    strdate = Format(strdate, "Short Date")

    On Error Resume Next
        Set rCell = Cells.Find(What:=CDate(strdate), After:=Range("A1"), LookIn:=xlFormulas _
            , LookAt:=xlWhole, SearchOrder:=xlByRows, SearchDirection:=xlNext, MatchCase:=False)
    On Error GoTo 0

    If rCell Is Nothing Then
        lReply = MsgBox("Date cannot be found. Try Again", vbYesNo)
        If lReply = vbYes Then Run "FindDate":
    End If
End Sub