Clickable Backgrounds

hey i was wondering how collegehumor.com implements a clickable background? every time i try it, it either doesn't work or the entire page becomes clickable. how do i make just the sides of the page clickable...the background. here's what i mean:

http://www.collegehumor.com/axe_target

thanks,.


PS. knowing how is nice...but can someone actually show me the code so i can do that on my site?

 

<h1 class="logo"><a href="/" onclick="urchinTracker('_gTrack/topNav/click/logo');"><span>CollegeHumor</span></a></h1>

Code (markup):

Javascript.

 

hm, im not really sure how this works. what does the code you sent me do? what is urchin tracker?

 

the best way to do it is to express the background image in the css.

#logo{
width:50px;
height:120px;
background:url(../images/mylogo.jpg) no-repeat;
display:block
}

<a href="mysiteurl.com" id="logo"></a>

Code (markup):