function cC(menu, newclass)
{
  document.getElementById(menu).className = newclass;
}


function showArrow(sub_arrow)
{
  arrow = document.getElementById(sub_arrow);
  arrow.className = "arrow";

  switch (sub_arrow) {
  case "arrow1":
	cC("arrow0", "arrow_hide");
	cC("arrow2", "arrow_hide");
	cC("arrow3", "arrow_hide");
	cC("arrow4", "arrow_hide");
	break;
  case "arrow2":
	cC("arrow0", "arrow_hide");
	cC("arrow1", "arrow_hide");
	cC("arrow3", "arrow_hide");
	cC("arrow4", "arrow_hide");
	break;
  case "arrow3":
	cC("arrow0", "arrow_hide");
	cC("arrow1", "arrow_hide");
	cC("arrow2", "arrow_hide");
	cC("arrow4", "arrow_hide");
	break;
  case "arrow4":
	cC("arrow0", "arrow_hide");
	cC("arrow1", "arrow_hide");
	cC("arrow2", "arrow_hide");
	cC("arrow3", "arrow_hide");
	break;
  default:
	break;
  }
}


function showSub(menu)
{
  submenu = document.getElementById(menu);
  submenu.className = "submenu";

  switch (menu) {
  case "sub1":
	cC("sub2", "submenu_hide");
	cC("sub3", "submenu_hide");
	cC("sub4", "submenu_hide");
	break;
  case "sub2":
	cC("sub1", "submenu_hide");
	cC("sub3", "submenu_hide");
	cC("sub4", "submenu_hide");
	break;
  case "sub3":
	cC("sub1", "submenu_hide");
	cC("sub2", "submenu_hide");
	cC("sub4", "submenu_hide");
	break;
  case "sub4":
	cC("sub1", "submenu_hide");
	cC("sub2", "submenu_hide");
	cC("sub3", "submenu_hide");
	break;
  default:
	break;
  }
}