var preloadFlag = false;
function preloadImages() {
	if (document.images) {
		banner_13_over = newImage("images/mainbnr/banner-13_over.gif");
		banner_18_down = newImage("images/mainbnr/banner-18_down.gif");
		banner_14_over = newImage("images/mainbnr/banner-14_over.gif");
		banner_19_down = newImage("images/mainbnr/banner-19_down.gif");
		banner_15_over = newImage("images/mainbnr/banner-15_over.gif");
		banner_20_down = newImage("images/mainbnr/banner-20_down.gif");
		banner_16_over = newImage("images/mainbnr/banner-16_over.gif");
		banner_21_down = newImage("images/mainbnr/banner-21_down.gif");
		banner_17_over = newImage("images/mainbnr/banner-17_over.gif");
		banner_22_down = newImage("images/mainbnr/banner-22_down.gif");
		preloadFlag = true;
	}
}