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

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

function changeImages() {
	changeImagesArray(changeImages.arguments);
}

function toggleImages() {
	for (var i=0; i<toggleImages.arguments.length; i+=2) {
		if (selected == toggleImages.arguments[i])      changeImagesArray(toggleImages.arguments[i+1]);
	}
}

var selected ='head_contact';
var preloadFlag = false;
function preloadImages() {
	if (document.images) {
		head_home_over = newImage("images/head_home-over.gif");
		head_home_head_aboutus_sel = newImage("images/head_home-head_aboutus_sel.gif");
		head_aboutus_head_home_sel = newImage("images/head_aboutus-head_home_sel.gif");
		head_aboutus_over = newImage("images/head_aboutus-over.gif");
		head_programmes_head_home_sel = newImage("images/head_programmes-head_home_s.gif");
		head_programmes_over = newImage("images/head_programmes-over.gif");
		head_fundraising_head_home_sel = newImage("images/head_fundraising-head_home_.gif");
		head_fundraising_over = newImage("images/head_fundraising-over.gif");
		head_news_head_home_sel = newImage("images/head_news-head_home_sel.gif");
		head_news_over = newImage("images/head_news-over.gif");
		head_contact_head_home_sel = newImage("images/head_contact-head_home_sel.gif");
		head_contact_over = newImage("images/head_contact-over.gif");
		head_contact_sel = newImage("images/head_contact-sel.gif");
		preloadFlag = true;
	}
}