Javascript in AMS

Is it possible to run oraor include a javascript snippet in AMS? I saw an example of facebook app by Urich Peter's, he included a json plugin and was able to work with json records, I want similar thing for javascript parsing json data in some manner. I just want to know if this is possible.

Thanks for a response. If an example is somewhere on the forum. Just point me there. Cos, I can't catch one till now.