(Replied to pm.)
In short, you need something like
Code:
.smartBG_19 #logoWrapper {
background-image: url(../images/smartbg_19.gif);
...
}
.smartBG_5 #logoWrapper {
background-image: url(../images/smartbg_5.gif);
...
}
.smartBG_13 #logoWrapper {
background-image: url(../images/smartbg_13.gif);
...
}
assuming 19, 5 and 13 are the category ids.
P.S. - I forgot to mention in the pm that header_5.jpg won't work. You need to name it smartbg_##, and the code is written to use gifs, not jpgs. You can change the .gif references to .jpg if you want, but then they must all be jpgs.