var browser = navigator.appName.toLowerCase();
var agent = navigator.userAgent.toLowerCase();

//window.alert(browser);
//window.alert(agent);

//var ns3 = ( (browser.indexOf('netscape')!=-1) && (agent.indexOf("3") != -1) );
var	ns4 = (document.layers)? true:false
var	ie4 = (document.all)? true:false
var	ns6 = (document.getElementById)? true:false
//number of main site navigation divs:
var layNumber = 20;

// Generic show Layers/Div function for all browsers which can be used independantly from hideShow()
	function showLayer(id) {
		//if (ns3){}
		if (ns4) document.layers[id].visibility = "show";
		else if (ie4) document.all[id].style.visibility = "visible";
	 	else if (ns6) document.getElementById(id).style.visibility = "visible";
		else document.getElementById(id).style.visibility = "visible";
		if(id !='info') {
		hideLayer('info')
		}
	}
	
// Generic Hide Layers/Div function for all browsers which can be used independantly from hideShow()	
	function hideLayer(id) {
		//if (ns3){}
		if (ns4) document.layers[id].visibility = "hide";
		else if (ie4) document.all[id].style.visibility = "hidden";
		else if (ns6) document.getElementById(id).style.visibility = "hidden";
		else document.getElementById(id).style.visibility = "hidden";
	}	
	
// Hides all Layers/Divs in var layNumber which can be used independantly from hideShow()
	//for main site navigation
	function hideAll() {
		for (var i=1; i<=layNumber; i++)	{
				hideLayer("lay"+i);
		}
		showLayer('info')
	}
	
// Calls the hideAll function then shows the relevant Layers/Div by ID	
	function hideShow(id) {
		hideAll();
		showLayer(id);
	}