var last_menu_no = 0, last_submenu_no = 0;

function om(element_no_1, element_no_2){
	// switch of active elements
	if(document.getElementById('sub'+last_menu_no)){
		document.getElementById('sub'+last_menu_no).style.display = 'none';
	}
	if(document.getElementById('cm'+last_menu_no)){
		document.getElementById('cm'+last_menu_no).className = 'menu';
	}
	if(document.getElementById('csm'+last_submenu_no)){
		document.getElementById('csm'+last_submenu_no).className = 'submenu';
	}

	last_menu_no = element_no_1;
	last_submenu_no = element_no_2;

	if(document.getElementById('sub'+last_menu_no)){
		document.getElementById('sub'+last_menu_no).style.display = 'block';
	}
	if(document.getElementById('cm'+last_menu_no)){
		document.getElementById('cm'+last_menu_no).className = 'menu-active';
	}
	if(document.getElementById('csm'+last_submenu_no)){
		document.getElementById('csm'+last_submenu_no).className = 'submenu-active';
	}
}