var preLoadFlag = "false";

	function preLoadImg(){
		arrImgList = new Array (
			"./img/home_on.jpg","./img/concept.jpg","./img/access_on.jpg","./img/gallery_on.jpg","./img/layout_on.jpg","./img/security_on.jpg","./img/outline_on.jpg","./img/contact.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;
		}
	}