// for the main nav

var isW3C = (document.getElementById) ? true : false
var isAll = (document.all) ? true : false

function showhidelayer(elemID) {
	var elem = (isW3C) ? document.getElementById(elemID) : ((isAll) ? document.all[elemID] : null);

    if (typeof elem.className == "string") {
        if (elem.className == 'closed'){
			elem.className = '';
		} else {
			elem.className = 'closed';
		}
    }
}