HTMLElement.prototype.click = function() {
	if (document.createEvent) {
		var evt = this.ownerDocument.createEvent('MouseEvents');
		evt.initMouseEvent('click', true, true, this.ownerDocument.defaultView, 1, 0, 0, 0, 0, false, false, false, false, 0, null);
		this.dispatchEvent(evt);
	} else if (this.fireEvent) {
		this.fireEvent("onclick");
	}
}
 
// usage
// <a href="http://www.barattalo.it" id="linktoclick">auto click</a>
document.getElementById("linktoclick").click();