addLoadListener(activateSlide);

var divHeight = 500;

function activateSlide() {
	var slideMenu = document.getElementById('selected_work');
	var slideMenuItems = slideMenu.getElementsByTagName('a');
	for (i=0; i<slideMenuItems.length; i++) {
		slideMenuItems[i].onclick = function() {
			resetMenu();
			slideContent(((this.id).substr(4))-1);
			this.className = 'active';
			return false;
		};
	}
}

function resetMenu() {
	var slideMenu = document.getElementById('selected_work');
	var slideMenuItems = slideMenu.getElementsByTagName('a');
	for (i=0; i<slideMenuItems.length; i++) {
		slideMenuItems[i].className = '';
	}
}


function slideContent(position) {
	var slidePosition = -(position*divHeight);
	var slideContent = new YAHOO.util.Anim('main_stage_content', { top: {to: slidePosition}}, 1, YAHOO.util.Easing.easeOut);
	slideContent.animate();
}


function addLoadListener(fn) {
	if (typeof window.addEventListener != 'undefined') {
		window.addEventListener('load', fn, false);
	} else if (typeof document.addEventListener != 'undefined') {
		document.addEventListener('load', fn, false);
	} else if (typeof window.attachEvent != 'undefined') {
		window.attachEvent('onload', fn);
	} else {
		var oldfn = window.onload;
		if (typeof window.onload != 'function') {
			window.onload = fn;
		} else {
			window.onload = function() {
				oldfn();
				fn();
			};
		}
	}
}