index.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="utf-8">
    <title>Photo Gallery</title>
    <link rel="stylesheet" href="gallery.css">
    <script src="gallery.js"></script>
</head>
<body>
    <div id="image">
        Hover over an image below to display here.
    </div>

    <img class="preview" alt="With My Boy" src="https://s3-us-west-2.amazonaws.com/s.cdpn.io/389177/bacon2.JPG"
        onmouseover="upDate(this)" onmouseout="unDo()">

    <img class="preview" alt="Styling with a Bandana"
        src="https://s3-us-west-2.amazonaws.com/s.cdpn.io/389177/bacon.jpg" onmouseover="upDate(this)"
        onmouseout="unDo()">

    <img class="preview" alt="Young Puppy"
         src="https://s3-us-west-2.amazonaws.com/s.cdpn.io/389177/bacon3.jpg" 
        onmouseover="upDate(this)" onmouseout="unDo()">
</body>
</html>