I had a quick look and have made some comments. It looks promising Lene -- Lene Nielsen Dept. Of Informatics Copenhagen Business School Howitzvej 60 2000 Frederiksberg T:+45 3815 3358 Fax: +45 3815 2401 Mobile: +45 28707763 http://experts.cbs.dk/index.asp?func=6.html&id=193