Background Image on Advanced Guestbook

Having trouble adding a background image to Advanced Guestbook 2.3.1.

I have added a gif image to template folder. I have tried editing the the header.tpl in diferent ways with no luck:

<body background="m_b.gif" link="$VARS[link_color]" vlink="$VARS[link_color]">

I get a white background.

I have tried adding the image name to the background color of styles and chnanged in the header:
<body backgound="$VARS[pbgcolor]" link="$VARS[link_color]" vlink="$VARS[link_color]">

I get a white background

Can anyone help? What do I need to do to get a background image instead of background color??

I found a Solution:
open the header.php

the search for the <style type="text/css">

and then insert
-----------------------------------------
body
{
background-image:
url("../images/back.gif")
}
------------------------------------------

view my Guestbook, it works -> http://mobileworld.verysurf.de/guestbook/

for more CSS Syntax see here ->
http://www.w3schools.com/css/css_background.asp

..:Hunter99:..