help with $ajax and json

help with $ajax and json

hi there!
I'm a bit new in jquery using $ajax. I'm implementing it using json. I'm using the automcomplete in combobox
I have a results.aspx which return json results. I just want it to display the results in the combobox autocomplete. the red part of the code is a bit confusing me on how can I do it. Actually I don't know how to handle the success part...

Here's the code:
<SCRIPT type="text/javascript">
        (function ($) {
            $.widget("ui.combobox", {
                _create: function () {
                    var self = this;
                    var select = this.element.hide();
                    var input = $("<input>")
.insertAfter(select)
.autocomplete({
   source: function (request, response) {
       $.ajax({
           url: "results.aspx",
           dataType: "jsonp",
           success: function (data) {
               alert('helo');
               return {
                   label: data[0].id,
                   value: data[0].name
               }
           }
       })
   },
   delay: 300,
   change: function (event, ui) {
       if (!ui.item) {
           // remove invalid value, as it didn't match anything
           $(this).val("");
           return false;
       }
       select.val(ui.item.id);
       self._trigger("selected", event, {
           item: select.find("[value='" + ui.item.id + "']")
       });

   },
   minLength: 3
})
.addClass("ui-widget ui-widget-content");
                    $("<button onclick='return false;'>&nbsp;</button>")
.attr("tabIndex", -1)
.attr("title", "Show All Items")
.insertAfter(input)
.button({
   icons: {
       primary: "ui-icon-triangle-1-s"
   },
   text: false
}).removeClass("ui-corner-all")
.addClass("ui-button-icon")
.click(function () {
   // close if already visible
   if (input.autocomplete("widget").is(":visible")) {
       input.autocomplete("close");
       return;
   }
   // pass empty string as value to search for, displaying all results
   input.autocomplete("search  ", "");
   input.focus();
});
                }
            });

        })(jQuery);

        $(function () {
            $("#combobox").combobox();
            $("#toggle").click(function () {
                $("#combobox").toggle();
            });
        });  
</SCRIPT>