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--;
	if (Ajax.activeRequestCount < 0) {
		Ajax.activeRequestCount = 0;
	}
};

Ajax.Updater.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--;
	if (Ajax.activeRequestCount < 0) {
		Ajax.activeRequestCount = 0;
	}
};