jquery autocomplete doesn't work?

I want to make autocomlplete for remote data source, I get all data from database and return it as jSon, using console I see that all data has been returned, but the autocomplete doesn't work, also the alert in my code doesn't work, here's my code

$("#cellPhoneNo").autocomplete({

    source: function(request, response) {
        var param = {
            "action": "getCellPhoneNos"
        };
        $.getJSON("controllers/Customer.controller.php", param, function(result) {
            alert('here'); //doesn't alert
            //  cellPhoneSource=result;
        });
    },
    select: function(event, ui) {
        alert('response');
    }

});

EDIT

I try to get the source using GET , I make like this

source:function(request,response){
            var param= {"action":"getCellPhoneNos"};
            $.ajax({
            type: "GET",
            url: "controllers/Customer.controller.php",
            data: param,
            success: function(result){
            alert('success');
            }

            });
            },

it alerts but aut开发者_开发问答ocomplete doesn't work, I try to put the values in a text file and make the file in the url , the autocomplete works!!

Any explanation?!

http://net.tutsplus.com/tutorials/javascript-ajax/how-to-use-the-jquery-ui-autocomplete-widget/

This is a tutorial on using the autocomplete plugin. The response variable in your callback is a function that you can call to add an array of items to the autocomplete list. Parse result and push each item onto an array, then call response(array); If result is already an array, you can call response(result);

I noticed that in the success function you do not return the result from the ajax query, could that be an issue?

source : function(request,response) {
     var param= {"action":"getCellPhoneNos"};
     var source = 'nothing came back from the server';

     $.ajax({
          type: "GET",
          url: "controllers/Customer.controller.php",
          data: param,
          datatype: 'json'
          success: function(result) {

            if(result !== undefined) {
                 source = result;
            }
            alert(source);
            return source;
          }

     });
},