After reading your problem, the $home variable really serves to save you from giving yourself carpal tunnel syndrome from typing out the full path.

For a moment, let's say you keep all your images to your site in the filesystem path /home/username/www/images/. Your web-based path to the script might be /cgi-bin/showpic. Now you want to log who is visiting each of your pages using this script without putting the same image on every page.

You could then set $home equal to '/home/username/www/images'. Then for each image that you want to have generate an entry in the log, you would set the src to '/cgi-bin/showpic/myHead.jpg' or '/cgi-bin/showpic/myHouse.jpg' or whatever.

However, if you have images all over your filesystem, you might set $home to '/home/username/www'. Then you image src could be '/cgi-bin/showpic/images/myHead.jpg' or '/cgi-bin/showpic/britain/bigben.jpg' or any other image you have on a page you want to log.