Loading gif image while jQuery ajax is running

I am trying to show a loading image while my ajax call is running, however using the beforeSend attribute is not changing my result area.

$.ajax({
  url: "/answer_checker.php",
  global: false, type: "POST", 
  data: ({...clipped...}), 
  cache: false,
  beforeSend: function() {
    $('#response').text('Loading...');
  },
  success: function(html) {
    $('#response').html(html);
  }
}

Thanks in advance.