Edit in JSFiddle

$("#search")
.onAsObservable("keyup change")
.select( (ev) -> $(ev.target).val())
.where( (query) -> query.length > 2)
.subscribe((query) -> queryMovie(query).then(updateMovies))

###
$("#search").on("keyup change", (ev)->
                   query = $(ev.target).val()
				   return if query.length < 3
				   queryMovie(query).then(updateMovies)
				)
###