Ajax post is not working

[eluser]bsrbvr[/eluser]
Hi, I tried with this but I am not getting result.

Code:

[removed]
$(document).ready(function(){
$('#offersearch').click(function () {
      var msg = $("#txtLocation").val();

  $.post(<?=base_url ?> +"location_ctrl/getLatLong", { 'item': msg },
   function(data){
  alert(data.result);
  }, "json");
    
});
});

[removed]

Thanks.