function et(ref) {
		if (ref=="mcs") {
			cat="MothsCount";
			label="Species Page";
		}
		if (ref=="alf") {
			cat="AngLeps";
			label="Footer Link";
		}
		if (ref=="bgf") {
			cat="Birdguides";
			label="Footer Link";
		}		
		if (ref=="alh") {
			cat="AngLeps";
			label="Home Page";
		}
		if (ref=="bgh") {
			cat="Birdguides";
			label="Home Page";
		}
		if (ref=="man") {
			cat="Manley";
			label="Book Page";
		}
		if (ref=="bcs") {
			cat="Butterfly Conservation";
			label="Species Page";
		}
		if (ref=="app") {
			cat="Birdguides App";
			label="App Page";
		}						
		action="Referral";		
		pageTracker._trackEvent(cat, action, label);
	}