Easy for use.
I tired a few approaches to this myself, and found your presentation to work out very well. It looked great. Love it. It did not work initially for IE7 and 8. Thanks to the awesome script debugging tools provided for IE [/sarcasm] 2 problems (I spent the better part of 4 hours tracing them). 1. The function call: window.open( this.popUpUrl, this.popUpName, this.popUpProps); in Spellchecker.js fails - after some looking, IE has a horrid implementation of window.open. Make sure the you have no spaces saved in your variable's values; Namely popUpName. 2. IE cannot open a window with a url located on another domain. It throws and exception.
It would have been nice if the index.html file is separated from actual spell checker files. If I have multiple pages where I need to use the spell checker, I would keep the spell checker files in a parent folder and access them by providing the path. It is not working that way. If I move the index.html page to some other folder outside of spell checker files, it is not working. I tried changing paths of other files but still no use.