function menu_highlight(page) {
	var btn = document.getElementById(page + "_btn");
	btn.className = "btn_div_over";
}

function reset(page) {
	var btn = document.getElementById(page + "_btn");
	btn.className = "btn_div";
}

function showLayer(id) {
	var layer = document.getElementById(id);
	layer.style.display="block";
}

function hideLayer(id) {
	var layer = document.getElementById(id);
	layer.style.display="none";
}