var mn_bg = new Image(); 
mn_bg.src = "/img/mn_bg.gif";

function center_t(h){
	t=(screen.height-h)/2;
	return t;
}
function center_l(w){
	l=(screen.width-w)/2;
	return l;
}

function topmenu_on(i){
	var mnup = eval("mn"+i+"up");
	document.getElementById("menu"+i).src = mnup.src;
}

function topmenu_off(i){
	var mn = eval("mn"+i);
	document.getElementById("menu"+i).src = mn.src;
}

function li_on(i){
	document.getElementById("li_"+i).className = "li_on";
}

function li_off(i){
	document.getElementById("li_"+i).className = "";
}

function menu_on(i){
	document.getElementById("menu_"+i).style.display = "block";
}

function menu_off(i){
	document.getElementById("menu_"+i).style.display = "none";
}