jQuery autocomplete not filtering and showing all the values

Question

I'm trying to populate auto suggestions with this javascript code but am unable to get it. I want to load data only if the first characters are matched to the entered data.

$(function() {

  $("#city").autocomplete(
  {
      search: function () {},
      source: function (request, response)
      {
          $.ajax(
          {
              url: 'getcities.php',
              dataType: "json",
              data:
              {
                  term: request.term,
              },
              success: function (data)
              {
                  response(data);
              }
          });
      },
      minLength: 2,
      select: function (event, ui)
      {

      }
  });

});

My json format is like this

[
    {"id":"1","name":"Mumbai"},
    {"id":"2","name":"Delhi"}
]