>My question is what do other people do for validation in their web pages?

Well, in the case of mandatory fields, you always want to update on the server. However, nothing says you can't validate both places. What does this do for you? Client Side script saves a round trip to the server, and should make the user a little happier.

So what you've got, is a bullet proof server side (business objects), plus, some time saving validation on the client side (keep the client sid'es validtion simple).