function showSubMenu(whichMenu) {

//alert(whichMenu)

//tempUrl = parent.main.document.title;

if (whichMenu != "") {

parent.topNav.document.getElementById('aboutSub').style.visibility = 'hidden';
parent.topNav.document.getElementById('direct').style.visibility = 'hidden';
parent.topNav.document.getElementById('events').style.visibility = 'hidden';
parent.topNav.document.getElementById('itiGrps').style.visibility = 'hidden';
parent.topNav.document.getElementById('bulletin').style.visibility = 'hidden';
parent.topNav.document.getElementById('av').style.visibility = 'hidden';
parent.topNav.document.getElementById('getSrt').style.visibility = 'hidden';
parent.topNav.document.getElementById('advice').style.visibility = 'hidden';
parent.topNav.document.getElementById('faq').style.visibility = 'hidden';
parent.topNav.document.getElementById('shop').style.visibility = 'hidden';
parent.topNav.document.getElementById('link').style.visibility = 'hidden';
parent.topNav.document.getElementById('contact').style.visibility = 'hidden';
parent.topNav.document.getElementById('home').style.visibility = 'hidden';
parent.topNav.document.getElementById('join').style.visibility = 'hidden';
parent.topNav.document.getElementById('blankBox').style.visibility = 'hidden';

parent.topNav.document.getElementById(whichMenu).style.visibility = 'visible';

}

}