function preloadImgs()
{
	nav1 = new Image();
	nav1.src = "images/nav-aboutus.jpg";
	nav2 = new Image();
	nav2.src = "images/nav-environment.jpg";
	nav3 = new Image();
	nav3.src = "images/nav-environmentLt.jpg";
	nav4 = new Image();
	nav4.src = "images/nav-knowledge.jpg";
	nav5 = new Image();
	nav5.src = "images/nav-knowledgeLt.jpg";
	nav6 = new Image();
	nav6.src = "images/nav-performance.jpg";
	nav7 = new Image();
	nav7.src = "images/nav-performanceLt.jpg";
	nav8 = new Image();
	nav8.src = "images/nav-play.jpg";
	nav9 = new Image();
	nav9.src = "images/nav-playLt.jpg";
}

function makeActive(id)
{
	document.getElementById(id).className="current";
}