Error on the advanced guestbook vcomment

i have a problem with the code verification when the user is filling up the information inside the guestbook , the verification code doesn't appear, and when the user submit a error appear,
i need help to solve this problem, thx

and i anyone would like to add a comment the same error appear .

so where is the problem

so you can visit http://www.vaincrelamucoauliban.org/guestbookphp

thx for your help

It says there is a problem loading the fonts.