Revealing images on hover

Revealing an image when another image is hovered.

HTML

<img id="imageToHover" src="http://img.photobucket.com/albums/v352/pootietang000/Tweet_To_Download_The_Song_zpsc5d7d33e.png" /><br>
<img id="imageToShow" src="http://www.polyvore.com/cgi/img-thing?.out=jpg&size=l&tid=10011783" />

CSS

#imageToShow{
    display: none;
}

JavaScript

document.getElementById('imageToHover').onmouseover = function() {
    document.getElementById('imageToShow').style.display = 'inline';   
}

document.getElementById('imageToHover').onmouseout = function() {
   document.getElementById('imageToShow').style.display = 'none';   
}