Creating an ajax spinner with spin.js

main.js

var spinnerOpts = {
  lines: 10,
  length: 7,
  width: 3,
  radius: 3,
  trail: 40,
  speed: 1.0
};

$.fn.spin = function(opts) {
  this.each(function() {
    var $this = $(this),
    spinner = $this.data('spinner');

    if (spinner) spinner.stop();
    if (opts !== false) {
      opts = $.extend({color: $this.css('color')}, opts);
      spinner = new Spinner(opts).spin(this);
      $this.data('spinner', spinner);
    }
  });
  return this;
};

  /* add ajax spinner */
  $("body").ajaxStart(function () {
    var elt = $('<div id="spinner"></div>');
    elt.css({top: '15px',
             left: '-30px',
             position: 'relative'});
    elt.spin(spinnerOpts);
    $("#top .contents").prepend(elt);
  })
    .ajaxStop(function () {
      $("#spinner").remove();
    });