I\'m using pretty much the this process oulined here to allow javascript to call objective c from my iPad app:
http://www.stevesaxon.me/posts/2011/window-external-no
So I used this blog entry to make things work: http://blog.techno-barje.fr/post/2010/10/06/UIWebView-secrets-part3-How-to-properly-call-ObjectiveC-from-Javascript/