/*
display the appropriate "sub nav" links.
accepts object or object id
*/
function viewSubNav(parentNav) {
	// find the parent object if it wasn't passed
	var obj = (typeof(parentNav) != "object") ? document.getElementById(parentNav) : parentNav;
	
	// find the sub nav object
	var objSubNav = document.getElementById(obj.id+'SUB');
	var sCurrDisplay = objSubNav.style.display;
	
	// display or hide sub nav
	if (sCurrDisplay == "none" || sCurrDisplay == "") {
		obj.className = "rollDown";
		objSubNav.style.display = "block";
	} else {
		obj.className = "rollUp";
		objSubNav.style.display = "none";
	}
	obj.blur();
} // viewSubNav()