This mission is hard to give tips on with out giving the answer.
What you need to work with is in the source and it has an extension. I cant say anymore really with out giving you the exact answer.
I will say that while you continue to learn HTML/XHTML put a lot of focus in to the navigation bar and how files work and connect to one another.
ALSO! There is a book called Head First HTML/XHTML with CSS. A great book to read for first timers.
They also write many other books, There Java book got me my A in my JAVA 2 class.http://www.headfirstlabs.com/index.php
- where to get good books.http://www.w3schools.com/
- great site for learning and looking up code snippets. http://www.w3.org/
- this is a site used to make sure your websites validate. If you know what needs to be validated then its easy to point out what is not.