function preloadImages() {
	if (document.images) {
		pre_navi_01over = newImage('/img/navi_01over.gif');
		pre_navi_02over = newImage('/img/navi_02over.gif');
		pre_navi_03over = newImage('/img/navi_03over.gif');
		pre_navi_04over = newImage('/img/navi_04over.gif');
		pre_navi_05over = newImage('/img/navi_05over.gif');
		pre_navi_06over = newImage('/img/navi_06over.gif');
		pre_navi_07over = newImage('/img/navi_07over.gif');
		pre_navi_08over = newImage('/img/navi_08over.gif');
		pre_navi_09over = newImage('/img/navi_09over.gif');
		pre_navi_10over = newImage('/img/navi_10over.gif');
		preloadFlag = true;
	}
}