example_ajax_form.js

$(this).submit(function(){
          $.ajax({
            type: 'POST',
            url: $(this).attr('action'),
            data: $(this).serialize(),
            success: function(data, status, xhr){
              my_function_goes_here(data);
            },
            error: function(data,status,xhr) {
              console.log(xhr);
              console.log(data.responseText);
            }
          });
          return false;
       });