PaymentMeans doubt

Hi (again).

    I'm building a UBL Invoice.

    I'm trying to put the invoice DuePaymentDate. Looking at the sxc I see
that cac:PaymentMeans has this element.

    However, when I make the xml as

  <cac:PaymentMeans>
    <DuePaymentDate>2004-05-05</DuePaymentDate>
  </cac:PaymentMeans>

    and run the parser, I get this error:

tag name "DuePaymentDate" is not allowed. Possible tag names are:
<PaymentMeansTypeCode>

    I can't find this in the xsi. Where is it? I'm looking at
UBL-Reusable-1.0.sxc and PaymentMeans has no reference to such tag.

    Thanks

-- 
Pedro Miguel G. Alves       
COMPTA - Parceria e Tecnologia      www.compta.pt
Tel:   +351 21 413 46 00  Av. José Gomes Ferreira
Fax:   +351 21 413 46 09     nº 13 1495-139 ALGÉS