Taking user input and storing into selected cell

[kal_e...@yahoo.com]

I want the user to be able to enter latex into an input box. A preview is shown to the user. I want to take this preview and store it into a selected cell.

So, I have something like this:

<p>Enter Latex:
<input id="input" onchange="render()" />
</p>

<p>Preview:</p>
<div class="box">
<div id="output" class="output"></div>
</div>

I also have a button. I just don't know how to make button take the stuff from output and store it into a cell with the same format it is in.