Untitled

<html>
<head>``
</head>
<body>
<img src="images/test"
<br><br><br>
<button>Click to change image!</button>
</body>
</html>

<html>
<head>
<script>

function changeImage()
{
var img = document.getElementById("image");
img.src="images/test2";
return false;
}

</script>

</head>
<body>
<img id="image" src="images/test" />
<br><br><br>
<button id="clickme" onclick="changeImage();">Click to change image!</button>
</body>
</html>