function newImage(arg) {
	if (document.images) {
		rslt = new Image();
		rslt.src = arg;
		return rslt;
	}
}

function changeImages() {
	if (document.images && (preloadFlag == true)) {
		for (var i=0; i<changeImages.arguments.length; i+=2) {
			document[changeImages.arguments[i]].src = changeImages.arguments[i+1];
		}
	}
}

var preloadFlag = false;
function preloadImages() {
	if (document.images) {
		nav_public_over = newImage("images/nav-public_over.gif");
		nav_investment_over = newImage("images/nav-investment_over.gif");
		nav_retirement_over = newImage("images/nav-retirement_over.gif");
		nav_employment_over = newImage("images/nav-employment_over.gif");
		nav_contact_over = newImage("images/nav-contact_over.gif");
		nav_home_over = newImage("images/nav-home_over.gif");
		index_nav_public_over = newImage("images/index_nav-public_over.gif");
		index_nav_investment_over = newImage("images/index_nav-investment_over.gif");
		index_nav_retirement_over = newImage("images/index_nav-retirement_over.gif");
		index_nav_employment_over = newImage("images/index_nav-employment_over.gif");
		index_nav_contact_over = newImage("images/index_nav-contact_over.gif");
		index_nav_home_over = newImage("images/index_nav-home_over.gif");
		preloadFlag = true;
	}
}