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


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


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

var preloadFlag = false;
function preloadImages() {
	if (document.images) {
		pre_navigation_on_01 = newImage('images/interface/buttons_on/navigation_on_01.jpg');
		pre_navigation_on_02 = newImage('images/interface/buttons_on/navigation_on_02.jpg');
		pre_navigation_on_03 = newImage('images/interface/buttons_on/navigation_on_03.jpg');
		pre_navigation_on_05 = newImage('images/interface/buttons_on/navigation_on_05.jpg');
		pre_navigation_on_06 = newImage('images/interface/buttons_on/assess_over.jpg');
		pre_navigation_on_07 = newImage('images/interface/buttons_on/qa_over.jpg');
		pre_navigation_on_08 = newImage('images/interface/buttons_on/team_over.jpg');
		preloadFlag = true;
	}
}