function menuToggle(id)
{
	obj = document.getElementById(id);
	obj_sub = document.getElementById(id + '_sub');

	if (obj_sub.className == 'menu_dropdown_hide')
	{
		obj_sub.className = 'menu_dropdown_show';
		obj.style.backgroundImage='url("/image/main/d.gif")';
	}
	else {
		obj_sub.className = 'menu_dropdown_hide';
		obj.style.backgroundImage='url("/image/main/r.gif")';
	}
}