Private Function FilterDateInterval(ByVal Columnname As String, _
    ByVal FirstDate As DateTime, ByVal Lastdate As DateTime) As String
 
    Dim ic As Globalization.CultureInfo = _
            Globalization.CultureInfo.InvariantCulture
    Dim sdp As String = ic.DateTimeFormat.ShortDatePattern
 
    Return Columnname & ">=#" & FirstDate.ToString(sdp, ic) & _
        "# AND " & Columnname & "<=#" & Lastdate.ToString(sdp, ic) & "#"
 
End Function