Disable FCKeditor (replace by a textarea)

Hello,

My application is AJAX based : EklaBlog.com (I currently use TinyMCE but I would like install FCKeditor)
My problem is that I need disable a textarea which has been replaced by FCKeditor, while deleting iframes and the FCK instance. (The page is never refreshed, and different textareas appear and disappear... I don't want leaks...).
An idea ?

Thanks for your great work !
(Sorry for my bad english...)