html validation

Hi,

I have added tidy tests (the test itself is badly tested as there is no
positive !). As Adrian said validation would be nice too. Uploading files
is an interesting option because the onlinr w3c interface is very nice, 
however it would be also usefull to have automated validation for tests. Do 
somebody know where to find a validator (I didn't find a simple explaination
on the w3c site) and some doc on how to call it ?

Pat