自动完成无法处理JSON文件

I need your help. I'm trying to put an autocomplete on dynamically create text input but I have got some problem. I would like to use the JSON file because the ajax request took 1/2 sec and for my use it's too much.

Here is the code:

$(document).on('keydown.autocomplete',"[id$=_buy_mod]",function() {    

   $(this).autocomplete({        
      source: function(request,response) {
          $.ajax({
              ttpe: "GET",
              url: "js/articoli.json",

              data: {
                  term: request.term
              },
              dataType:'json',
              dataFilter: function(data) {return data;},
              success: function(data) {
                  response($.map(data,function(product) {

                      return {
                          label: product.label,
                          value:product.value

                      };
                  }))

              },

          })
      },
      minLength: 1,
      select: function( event, ui ) {
          var localid = $(this).attr('id');
          var numerolocal = localid.match(/\d+/);
          console.log(numerolocal);
          $(this).val(ui.item.label);
          $("[id$="+numerolocal+"_buy_id_mod]").val(ui.item.value)

          return false;

      }
   });

Actually timing is good but autocomplete is not filtering data and it show me all possible words.

Here is the json file

[{"value": "1","label": "Panasonic Lumix L1"}, 
{"value": "10","label": "Sigma 17-50mm f 2.8 OS Canon"}, 
{"value": "11","label": "Canon 1000D"}, 
{"value": "1100D","label": "Canon 1100D"}
-------

How can I solve?