/* some basic wob functions
	most - if not all - of them require mootools v1.1
*/

/**
 * add event listener for mouseover on main nav
 */
function observeMainNav() {
	var altNavImgs = new Array;
	var navImgs = $$('div[id="topnav"] a img');
	for (var i=0; i<navImgs.length; i++) {
		// preload swap images
		altNavImgs[i] = $(navImgs[i].cloneNode(true)); 
		altNavImgs[i].src = navImgs[i].src.replace(/_off\.gif/,"_on.gif");
		// observe only images which are initially off
		if ( navImgs[i].src.match(/_off\.gif$/) ) {
			navImgs[i].addEvent('mouseover', observeActionImgSwapOn);
		}
	}
}
	/**
	 * Helper Function to swap images off
	 */
	function observeActionImgSwapOff(e) {
		var event=new Event(e);
		var elem=event.target;
		if (elem.src.match(/_on\.gif$/) ) {
			elem.src = elem.src.replace(/_on\.gif/,"_off.gif");
		}
		elem.removeEvent('mouseout', observeActionImgSwapOff);
		elem.addEvent('mouseover', observeActionImgSwapOn);
	}
	/**
	 * Helper Function to swap images on
	 */
	function observeActionImgSwapOn(e) {
		var event=new Event(e);
		var elem=event.target;
		if (elem.src.match(/_off\.gif$/) ) {
			elem.src = elem.src.replace(/_off\.gif/,"_on.gif");
		}
		elem.removeEvent('mouseover', observeActionImgSwapOn);
		elem.addEvent('mouseout', observeActionImgSwapOff);
	}
	
window.addEvent('domready', observeMainNav);