Stretching Image

HTML

<div id="background">
    <img src="http://upload.wikimedia.org/wikipedia/commons/f/fe/CSSShenandoah.jpg" class="stretch" alt="" />
</div>

CSS

#background {
    width: 100px; 
    height:400px; 
    position: fixed; 
    left: 0px; 
    top: 0px; 
    z-index: -1; /* Ensure div tag stays behind content; -999 might work, too. */
}

.stretch {
    width:100%;
    height:100%;
}