function show_menu(menu_name) {
	hide_menu();
	var menu = document.getElementById(menu_name+'_menu');
	var item = document.getElementById(menu_name+'_item');
	menu.style.display = '';
	menu.style.left= getElementPosX(item) + getElementWidth(item);
	menu.style.top = getElementPosY(item);
}

function hide_menu(except) {
	var tables = document.getElementsByTagName('table');
	for( var i=0; i<tables.length; i++ ) {
		if( tables[i].className == 'menu' && tables[i].id != except+'_menu' ) {
			tables[i].style.display = 'none';
		}
	}
}