help me about Virus in my Advance Guestbook

someone can post many topic and include link every topic.

And then, I call my page ( http://www.musichandmade.com/guestbook )
I found Virus every time

Please help me

Somebody has abused the fact you have HTML enabled to put an iframe in an entry which then points to a PHP script which starts a download of a virus. You need to delete the last post you had as this is the malicious post and DISABLE HTML.