I can specify CSS like this: background: #CFCFCF url(button.bmp) repeat-x top; - but if I want an image for top along with images for left, right and bottom, how would I go about that?
You can only have one background image on an element. The
top in your example will set the background image to start from the top. You can use different combainations of these words such as
top left (begin background image from top left corner), or
bottom right (begin background image from bottom right corner), but you can't use
top bottom for example.
You can also use pixel measurements too, for example,
url(button.bmp) repeat-x top -30px; this would start the background image from the top edge, 30 pixels into the image. This is how CSS sprites are used.
These words are not for specifying different background images. CSS3 will bring multiple background images on an element.