XML Schema and parser

I'm trying to build an application that will use datas inside xml files. So, I've defined an XML schema for the structure of the xml files and the datatypes. In my xml file, I can put anything instead of correct date field and when i'm looking the file with IE5.0, there's no error at all.
So, I've difficulties to understand if XML schema works with IE5.0.
Thanks for your answers about that subject.
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William FERRERES
ADVANTYS (http://www.advantys.fr)
Tel : 04 93 18 73 20
Fax : 04 93 18 73 21