$.ajax({
  url: 'Service.asmx/Method',
  type: 'POST',
  contentType: 'application/json',
  data: '{"Parameters":"Must be JSON strings!"}',
  success: function(response) {
    // Don't forget that the response is wrapped in a
    //  ".d" object in ASP.NET 3.5 and later.
    console.log(response.d);

$.ajaxSetup({ cache: false });
$("#loading_animation").bind({
    ajaxStart: function() { $(this).show(); },
    ajaxStop: function() { $(this).hide(); }
});