Preview:
<!DOCTYPE HTML>
<html>
<head>
<meta charset="utf-8">
<title>Select box event</title>
<script type="text/javascript">
    function swapImage(hash) {
        document.getElementById('imageSwap').src = hash + '.jpg';
    }
</script>
</head>
<body>

<div id="builder_image">
    <img src="rw_blue.jpg" id="imageSwap" alt="" />
</div>

<select name="option3" onchange="swapImage(this.options[selectedIndex].label)">
    <option value="No thanks" selected="selected" label="rw_blue">No thanks</option>
    <option value="Blue" label="rw_blue">Blue</option>
    <option value="Black" label="rw_black">Black</option>
    <option value="Red" label="rw_red">Red</option>
</select>

</body>
</html>
downloadDownload PNG downloadDownload JPEG downloadDownload SVG

Tip: You can change the style, width & colours of the snippet with the inspect tool before clicking Download!

Click to optimize width for Twitter