top.isOpera = window.opera ? true : false;
top.isIE = (document.getElementById) && (document.all) && (!top.isOpera) ? true : false;
top.isNS = (document.getElementById) && (!document.all) && (!top.isSafari) ? true : false;
top.isMac = (navigator.userAgent.toUpperCase().indexOf("MAC") > -1) ? true : false;
top.isSafari = (document.childNodes) && (!document.all) && (!navigator.taintEnabled) && (!navigator.accentColorName) ? true : false;		
top.isIE5=false;
if (top.isIE){
	var appVersion=navigator.appVersion.match(/MSIE (\d\.\d)/)[1]
	if (top.isIE && appVersion<6 && !top.isMac){
		top.isIE5=true;
	}
}
top.isIEMAC=false;
if (top.isIE && top.isMac){
	//alert('Welcome! Please note: this site is not optimised for IE on Mac. \n\n It should be broadly functional but the layout may be compromised in places. \n\n Please consider using Safari / Firefox')
	top.isIEMAC=true;
}
if (top.isOpera){
	//alert('Welcome\n\nplease note: the layout of this site is not optimised for Opera. It should however function fully. Thanks!');
}