code to look up ad_id given hit_id

- necessary because AMT only present the experiment thread with the hitId.  You need to ask the api for how to lookup the ad.
a little better name for this

- overall, the experiment errors is need of improvement
dealing with complete hit.

WARNING... your task.js may need to be update to point to the correct URL to complete the hit (see new example)

var completeHIT = function() {
	// save data one last time here?
	window.location= adServerLoc + "?uniqueId=" + psiTurk.taskdata.id;
}