Dear Maxim,

Thank you for your posting! It was very helpfull. I didn't respond any
earlier because I didn't read my mail last week because of summer
holidays.

I've got an additional question: say I want to add an empty element
depending on whether the employee is hired (temporarily) from another
company or on the payrole of our own company.
The output should be:
<Medewerkerslijst ....>
<Medewerker>
<REGISTRATIENR>123456789</REGISTRATIENR>
<VOORNAAM>John</VOORNAAM>
<ACHTERNAAM>Jansen</ACHTERNAAM>
<VOORLETTERS>J</VOORLETTERS>
<GESLACHT>M</GESLACHT>
<GEBRUIKERSNAAM>xxx222</GEBRUIKERSNAAM>
<EMAIL>john@ourcompany.nl</EMAIL>
</EXTERN> ====>>> This element is lacking when an employee is
on the payrole of our own company
</Medewerker>
......
</Medewerkerslijst>

Any idea on how to achieve this? Any help is appreciated.

Kind regards,

Willy Tadema