function newImage(arg) {
	if (document.images) {
		rslt = new Image();
		rslt.src = arg;
		return rslt;
	}
}

function changeImages(id) {
	img = document.getElementById(id);
	src = img.src;
	path = src.substr( 0, src.lastIndexOf('/')+1 );
	ext = src.substr( src.lastIndexOf('.') );
	name = src.substr( path.length, src.length - path.length - ext.length );
	
	path = path.substr(7);
	path = path.substr( path.indexOf('/'));
	if ('_over' == name.substr( name.length-5 )) name = name.substr(0, name.lastIndexOf('_over'));
	else name += '_over';
	src = path + name + ext;
	img.src = src;
}

var preloadFlag = false;
function preloadImages() {
	if (document.images) {
		left_menu1_over = newImage("/images/left_menu1_over.gif");
		left_menu2_over = newImage("/images/left_menu2_over.gif");
		left_menu3_over = newImage("/images/left_menu3_over.gif");
		left_menu4_over = newImage("/images/left_menu4_over.gif");
		left_menu5_over = newImage("/images/left_menu5_over.gif");
		left_menu6_over = newImage("/images/left_menu6_over.gif");
		left_menu7_over = newImage("/images/left_menu7_over.gif");
						
		top_menu1_over = newImage("/images/top_menu1_over.gif");
		top_menu2_over = newImage("/images/top_menu2_over.gif");
		top_menu3_over = newImage("/images/top_menu3_over.gif");
		top_menu4_over = newImage("/images/top_menu4_over.gif");
		top_menu5_over = newImage("/images/top_menu5_over.gif");
		preloadFlag = true;
	}
}