I can't seem to do this anywhere.

I have this:

Code:
<div id="div-one">
//various rubbish inside
</div>

<div id="div-two>
//various rubbish inside
</div>
And I need jQuery to edit the HTML so that it results in this:

Code:
<div id="div-one">
//various rubbish inside
//various rubbish inside
</div>
I can't seem to do it. I've looked at before, after, insertBefore etc. but it doesn't work.