Does anyone know how to update a checkbox's status? I.e. I have 4 checkboxes, and the last one is an "all of the above" option, so when clicked I want it to automatically 'check' the other three boxes immediately.

It's related to javascript. I used the similar script before. You can do a google search on this kind of javascript.

In the onclick event, put a JS function call that checks all the other boxes.

Setting the box to checked is easy:

document.frmName.chkBoxName.checked = true;

www.devguru.com, is a decent JS reference that I use.