function show(obj)
{
	if(obj.style.display=="none") obj.style.display = "";
}
function hide(obj)
{
	if(obj.style.display=="") obj.style.display = "none";
}
function hide_all()
{
hide(introduction);
hide(reservation);
hide(preview);
hide(notice);
hide(direction);
}
function show_main()
{
hide_all();
}
function show_introduction()
{
hide_all();
show(introduction);
}
function show_reservation()
{
hide_all();
show(reservation);
}
function show_preview()
{
hide_all();
show(preview);
}
function show_notice()
{
hide_all();
show(notice);
}
function show_direction()
{
hide_all();
show(direction);
}