var imgLoaded = false;
var arrow_active, arrow_inactive;

	if (document.images) {

		arrow_active = new Image();
		arrow_inactive = new Image();
		arrow_active.src = 'images/arrow.gif';
		arrow_inactive.src = 'images/empty.gif';

		imgLoaded = true;
	}

function arrowOut(arrowNr) {
	if(imgLoaded)
		document.getElementById('arrow'+arrowNr).src = arrow_inactive.src
}

function arrowOver(arrowNr) {
	if(imgLoaded)
		document.getElementById('arrow'+arrowNr).src = arrow_active.src
}