jQuery UI Autocomplete: How can I pass additional data with my Ajax call?

Question

I have two jQuery UI Autocomplete widgets set up. With the first autocomplete, the user will enter a client's name - the autocomplete will narrow it down until the correct client has been chosen. I then have a callback that takes the ID of the client returned and puts it into a hidden input field.

Next, is a second autocomplete field. When searched in, this needs to send two variables to the server - the user's search string ( term ), and the User ID of the client that was searched for previously.

I have no problems dealing with the server side of things, but where I'm struggling is how to pass 2 variables to the Ajax call, rather than just term . In my PHP backend, I need to query against the User ID as well, to only return properties belonging to that user.

How can I do this?

Thanks!

Edit: Thanks to @JohnP, this was what I ended up - seems to work fine for me. Posting this here for reference for anyone in future who drops by:

source: function (request, response) {

    var request_data = {
        term: request.term,
        client_id: $('input#client_id_string').val()
    };

    var url = 'http://mysite.com/search/ajax_search';

    $.getJSON(url, request_data, function (data, status, xhr) {
         response(data);
    });
},

Answer 1

You can override the source method if it's a static method.

//code
source: function (request, response) {
    var term = request.term;
     //caching if yo uwant
     var myCustomVar = 42;

     $.getJSON(url + term + '/' + myCustomVar , request, function (data, status, xhr) {
          response(data);
     });
},
//code

You can either make it part of the URL or just pass it along with the request, if you want.