Extending Ajax Request object for aborting

prototype_extend.js

/**
 * Extend the Ajax.Request object to add function to abort() current Ajax Request
 * 
 * @source http://blog.pothoven.net/2007/12/aborting-ajax-requests-for-prototypejs.html
 */
Object.extend(Ajax.Request.prototype, {
  abort: function() {
    // prevent and state change callbacks from being issued
    this.transport.onreadystatechange = Prototype.emptyFunction;
    // abort the XHR
    this.transport.abort();
    // update the request counter
    Ajax.activeRequestCount--;
  }
});

Ajax.Responders.register({
  onComplete: function()
  {
    if (Ajax.activeRequestCount < 0) Ajax.activeRequestCount = 0;
  }
});