Autocompletion frustrations

[eluser]nlweb[/eluser]
[quote author="Aken" date="1345090291"]The data you send through an $.ajax() request needs to be a query string, or a Javascript array or object. Look it up yourself. All you're doing is passing a standard string - the value of your tags field. Therefore, you are not creating a POST request for "term", and it won't exist when it gets to your lookup() controller.[/quote]

According to that page it can be an object OR a string. I tried setting term to an object as well like you recommended, still no results, but I did some digging with FireBug, and anytime something is typed into the input box, it sends back a Server 500 error, "The action you have requested is not allowed."

EDIT: The parameters for the 500 error shows the correct variable "terms" with the correct text, so lookup IS getting the text in the input box.