var preloadFlag = false;
function preloadImages() {
	if (document.images) {
		pre_ad_zone6a = newImage('../../../images/ad-zone6a.png');
		pre_ad_zone5a = newImage('../../../images/ad-zone5a.png');
		pre_ad_zone2a = newImage('../../../images/ad-zone2a.png');
		pre_ad_zone1a = newImage('../../../images/ad-zone1a.png');
		pre_ad_zone3a = newImage('../../../images/ad-zone3a.png');
		pre_ad_zone4a = newImage('../../../images/ad-zone4a.png');
		preloadFlag = true;
	}
}