Removing code

Hi,

I am creating a page that contains a button like this: <a href="01.html"><div id="clickleft"></div></a>

This code is within a editable area, and when I make a change to the text in this area, SimpleCMS sometimes removes the link (<div id="clickleft"></div>) ]. Please could you let me know why this might be happening.

Here is the page: http://www.wellards.co.uk/papers/course … nt/02.html