/* 
	no configuration required here.  For this script to work, you must preload prototype-1.4.0.js
	
	the prototype library can be obtained here:  http://prototype.conio.net/
	
	or google for 'prototype javascript'
	
	questions? email Robert Hahn: rh@roberthahn.ca, http://roberthahn.ca
*/
					var vizLayer = '';

					function rh_hideMenus() {
						if (vizLayer == '') return;
						Element.hide(vizLayer);
						Element.hide('invisible_lyr');
						vizLayer = '';
					}

					function rh_showMenu(m) {
						Element.show(m);
						Element.show('invisible_lyr');
						vizLayer = m;
					}