I’ve recently stopped using javascript to do rollovers when reasonable. It’s much nicer because you don’t have to write onmouseover or onmouseout events, and it works without javascript. It’s also prevents a weird ‘blink’ (especially in IE) when rolling over if the image isn’t loaded in cache.

The trick is to create one image that has both states and assign the background-position of the hover state.

Using the following image and css, you don’t have to worry about javascript.

a.seeMore {
    background: #dce1e4
    url(/images/icons/arrowFull.gif)
    no-repeat top right;
}
a.seeMore:hover {
     background-color:#4f5a62;
     background-position:right -18px;
}