jQuery: Easiest way to wrap an image tag with an A anchor tag

This is a simplified version of my problem.

I have two buttons, and one image. The image code is something like this

<img class="onoff" src="image.jpg">

When I press button one I want the image to be wrapped in an A tag, like

<a href="link.html">
<img class="onoff" src="image.jpg">
</a>

And when I press the other button, the A tags should be removed.

What's the easiest way of doing this with jQuery?