Ajax Spell Checker

Currently am using spellingcow to check spelling error on any html textarea in a page. Prior to this, I've used ajax-spell checker to kick out all the spelling cow ads. But spellingcow still great at this time because it only require developer to add only one line code. But I still can't figure out how to enable spelling cow works on text input. So am still struggling to digg out the code of ajax-spell to make it works on my application