function show(id) {
	hide_all();
	document.getElementById(id).style.visibility = "visible";
}
function hide(id) {
	document.getElementById(id).style.visibility = "hidden";
}

function hide_all() {
hide('sub_menu_dvd');
hide('sub_menu_en');
hide('sub_menu_rimko');
hide('sub_menu_jurre');
}