var user_agent = ' ' + navigator.userAgent.toLowerCase();
var is_icab = user_agent.indexOf('icab') > 0;

var menus_ok = false;
if ((document.getElementById) && (is_icab == false)) {
	menus_ok = true;
}

// alert ('ua: '+user_agent+'\ris iCab: '+is_icab+'\rmenus OK: '+menus_ok);

function changeMenuVis(id, make_visible) {
	if (menus_ok) {
		if ((make_visible == true) && (document.getElementById(id).style.visibility != 'visible')) {
			document.getElementById(id).style.visibility = 'visible';
		}
		else if ((make_visible == false) && (document.getElementById(id).style.visibility != 'hidden')) {
			document.getElementById(id).style.visibility = 'hidden';
		}
	}
}