Dynamic form changes without refresh

Hiya all, I have a PHP page with a form holding a large number of textarea boxes. These text boxes are individually set as enabled or disabled based on a flag held in a MySQL database. I want to be able to dynamically enable or disable a specific box without the page being recalled (potentially loosing the parameters passed, and having to rebuild a large complex table). Using some basic javascript/AJAX, I have set up a link next to each text box, which calls code that updates the database in the background without refreshing the page. If I manually refresh the page, the textarea box in question updates correctly, proving that the database update has worked. However, I cannot work out how to get the textarea boxes to toggle the disable on/off "on the fly". I assume they would need to continually check the database and adjust as required. I realise there may not be too much PHP involved here, but I was wondering whether anyone could assist or point me in the right direction. Thanks, Jon.