Filter On A Date AND A Combo Box

Hello everybody,

I have a problem.
I want to apply a filter on my form.When I filter on the combobox it works fine.
But when I filter on the date the form jumps into the error handler. Below is the code that I use for my filter:

Sub ApplyFilter()
Dim sFilter As String
sFilter = ""


'Filter on date
If Me.txtFilterDatumMelding = "" Or IsNull(Me.txtFilterDatumMelding) Or Me.txtFilterDatumMelding = 0 Then
If sFilter = "" Then
sFilter = ""
Else
sFilter = sFilter & ""
End If
Else
If sFilter = "" Then
sFilter = "[DatumMelding] = " & "'" & txtFilterDatumMelding & "'"

Else
sFilter = sFilter & " and [DatumMelding] = " & "'" & txtFilterDatumMelding & "'"
End If
End If

'Filter on combobox
If Me.cboFilterCallMelder = "" Or IsNull(Me.cboFilterCallMelder) Or Me.cboFilterCallMelder = 0 Then
If sFilter = "" Then
sFilter = ""
Else
sFilter = sFilter & ""
End If
Else
If sFilter = "" Then
sFilter = "[CallMelder_ID] = " & cboFilterCallMelder
Else
sFilter = sFilter & " And [CallMelder_ID] = " & cboFilterCallMelder
End If
End If

If Len(sFilter) > 0 Then
Me.Filter = sFilter
Me.FilterOn = True
Else
Me.Filter = ""
Me.FilterOn = False
End If
End Sub

I hope that you gus can help me. Could it be that the filter is a string and the date filter field is a date??????

thanks in advance.