// written by Dean Edwards, 2005
// with input from Tino Zijdel, Matthias Miller, Diego Perini

// http://dean.edwards.name/weblog/2005/10/add-event/

function addEvent(element, type, handler) {
	if (element.addEventListener) {
		element.addEventListener(type, handler, false);
	} else {
		// assign each event handler a unique ID
		if (!handler.$$guid) handler.$$guid = addEvent.guid++;
		// create a hash table of event types for the element
		if (!element.events) element.events = {};
		// create a hash table of event handlers for each element/event pair
		var handlers = element.events[type];
		if (!handlers) {
			handlers = element.events[type] = {};
			// store the existing event handler (if there is one)
			if (element["on" + type]) {
				handlers[0] = element["on" + type];
			}
		}
		// store the event handler in the hash table
		handlers[handler.$$guid] = handler;
		// assign a global event handler to do all the work
		element["on" + type] = handleEvent;
	}
};
// a counter used to create unique IDs
addEvent.guid = 1;

function removeEvent(element, type, handler) {
	if (element.removeEventListener) {
		element.removeEventListener(type, handler, false);
	} else {
		// delete the event handler from the hash table
		if (element.events && element.events[type]) {
			delete element.events[type][handler.$$guid];
		}
	}
};

function handleEvent(event) {
	var returnValue = true;
	// grab the event object (IE uses a global event object)
	event = event || fixEvent(((this.ownerDocument || this.document || this).parentWindow || window).event);
	// get a reference to the hash table of event handlers
	var handlers = this.events[event.type];
	// execute each event handler
	for (var i in handlers) {
		this.$$handleEvent = handlers[i];
		if (this.$$handleEvent(event) === false) {
			returnValue = false;
		}
	}
	return returnValue;
};

function fixEvent(event) {
	// add W3C standard event methods
	event.preventDefault = fixEvent.preventDefault;
	event.stopPropagation = fixEvent.stopPropagation;
	return event;
};
fixEvent.preventDefault = function() {
	this.returnValue = false;
};
fixEvent.stopPropagation = function() {
	this.cancelBubble = true;
};


addEvent(window, 'load', setVisibleListeners);

function setVisibleListeners() {
	// starting from the result section, get the lists therein
	var results=document.getElementById('results');
	if (!results) return;
	var lists=results.getElementsByTagName('ul');
	// for each list ...
	for (var i=0, list=null; list=lists[i]; i++) {
		// skip any that aren't "sponsored" lists
		if ('sponsored'!=list.className) continue;

		// attach a mouseover and mouseout listener on these lists
		addEvent(list, 'mouseover', setVisLink);
		addEvent(list, 'mouseout', clearVisLink);
	}
}

function linkForEvent(event) {
	// stop processing if we aren't dealing with an <a> (or child of one)
	var el=event.target || event.srcElement;
	while (el && el.tagName && 'A'!=el.tagName) {
		el=el.parentNode;
	}
	if (!el || 'A'!=el.tagName) return null;

	return el;
}

function setVisLink(event) {
	var el=linkForEvent(event);
	if (!el) return;

	// find the visible URL inside this link
	var spans=el.getElementsByTagName('span');
	if (!spans || !spans[2]) return;

	window.status=spans[2].textContent || spans[2].innerText;
	
	// Keep the mouseover event from its default action: showing the URL.
	if (event.preventDefault) event.preventDefault();

	return true;
}

function clearVisLink(event) {
	var el=linkForEvent(event);
	if (!el) return;

	window.status='';
	return true;
}


addEvent(window, 'load', qFocus);

function qFocus() {
	var q=document.getElementsByName('q');
	if (q && q[0]) q=q[0];

	if (!q) return;

	q.focus();
}