//preload
function preload(){
	if (navigator.appVersion.charAt(0) >= "3") {
		for(idx=0; idx<imgname.length; idx++) {
			img[idx]=new Image();
			img[idx].src=preload_dir+imgname[idx];
		}
	}
}

//rollover
function rollover(nam,o){
	if (navigator.appVersion.charAt(0) >= "3"){
		document.images[nam].src=rollover_dir+o;
	} 
}