you might want to tone down the outer glow on the navigation text because it's looking like a mirage instead of clear read text.

which is the button to press to login..? issit the word Login or the word Submit..? no box around any of it so which is a button..?

i think this and the other one works. the reason it didn't go well with your teacher is because adults tend to get more confused with teen type websites. after all, target audience is rather different in terms of design.

cheers.