var preLoadFlag = "false";

	function preLoadImg(){
		arrImgList = new Array (
			"/misc/super_youth_on.jpg","/misc/premium_dream_on.jpg","/misc/dream_on.jpg","/misc/newdream_on.jpg","/misc/youth_dream_on.jpg",
			"/misc/youth_newdream_on.jpg","/misc/tokaido_on.jpg","/misc/chuodo_on.jpg","/misc/ladies_dream_on.jpg","/misc/super_newdream_on.jpg",
			"/misc/yokohama_harbor_on.jpg","/misc/keihanshin_dream_on.jpg","/misc/premium_on.jpg","/misc/youth_megadream_on.jpg",
			"/misc/allplan_on.jpg","/misc/timetable_on.gif","/misc/discount_on.gif",
			"/misc/button01_on.gif","/misc/button02_on.gif","/misc/ticket_button_on.gif","/misc/youth_special_on.jpg",
			"/img/button_blue_on.gif","/img/button_green_on.gif","/img/button_pink_on.gif","./img/timetable_button_on.jpg"
		);
		arrPreLoad = new Array();
		for (i in arrImgList) {
			arrPreLoad[i] = new Image();
			arrPreLoad[i].src = arrImgList[i];
		}
		preLoadFlag = "true";
	}

	function chgImg(fileName,imgName){
		if (preLoadFlag == "true") {
			document.images[imgName].src = fileName;
		}
	}