Change Div Background Image With Link Hover

When I hover back and forth over a link in one area of a page, the background-image of a div in another part of the page needs to change back and forth. I have been trying all sorts of things in jquery with no results!

Here's the jquery script...
Code:
$function() {
$("#about-lifebook").hover(over,out);
function over (event) {
$(.spacer-bg-off).css("background", "url(images/spacer-content-bg.png)");
} function out (event) {
$(.spacer-bg-off).css("background", "none");
});

The link's id is "about-lifebook" and the div in question has a class of "spacer-bg-off". This ain't working at all. I just read this off of the jquery website: "The .hover() method binds handlers for both mouseenter and mouseleave events. We can use it to simply apply behavior to an element during the time the mouse is within the element." So perhaps the behavior has to be applied to the element being hovered over? How can I change the css of one element while hovering over another one?