To get your boo to work you need to have this code in your sig
[I MG]http://i16.photobucket.com/albums/b2/cheryl1106/Halloween/icon_mickey_halloween.gif[/I MG]
However, when you do it for real, you need to delete the spaces in the [I MG] and [/I MG] I put those in, so you could see the code instead of it making the little bouncing Mickey.