function menu_change(id){
	i = document.getElementById(id);
	s = i.className;
	if(s=="menuitem"){
		i.className = "menuitem_hover";
	}else if(s=="menuitem_hover"){
		i.className = "menuitem";
	}else if(s=="sectionitem"){
		i.className = "sectionitem_hover";
	}else if(s=="sectionitem_hover"){
		i.className = "sectionitem";
	}
}

function show(id){
	document.getElementById(id).style.display = 'block';
}
function hide(id){
	document.getElementById(id).style.display = 'none';
}
function toggle(id){
	i = document.getElementById(id);
	if(i.style.display=="none"){
		i.style.display = "block";
	}else{
		i.style.display = "none";
	}
}