step 1... left-click where it says "sign guestbook" and the guestbook will expand

step 2... type something in where it says name (it must have something in it... a single letter will do)

step 3... type something in the message box

step 4... type the code into the code box (bottom-left of the page)

step 5... left-click the submit button (bottom-right of the page)