function track() {
	var sTerm = '';
	if ((document.referrer != '') && (document.referrer.indexOf('instantatlas.com') < 0)) {
		setCookie('iaReferredFrom', document.referrer, 0); // expires today
		if (document.referrer.indexOf('?') > 0) {
			var qs = document.referrer.substring(document.referrer.indexOf('?') + 1);
			// Google
			if (qs.indexOf('q=') >= 0) {
				sTerm = qs.substring(qs.indexOf('q=') + 2);
				if (sTerm.indexOf('&') > 0)
					sTerm = sTerm.substring(0, sTerm.indexOf('&'));
				sTerm = unescape(sTerm);
			}
			setCookie('iaReferralSearchTerm', sTerm, 0); // expires today
		}
	}
	sTerm = getCookie('iaReferralSearchTerm');
	var i = document.getElementById('searchterm');
	if ((i != null) && (sTerm != null) && (sTerm != '')) {
		i.value = sTerm;
	}
}

function setCookie(cookieName, cookieValue, nDays) {
	var expires = '';
	if (nDays) {
		var date = new Date();
		date.setTime(date.getTime() + (nDays*24*60*60*1000));
		var expires = '; expires=' + date.toGMTString();
	}
	document.cookie = cookieName + '=' + cookieValue + expires + '; path=/';
}

function getCookie(cookieName) {
	var nameEQ = cookieName + '=';
	var ca = document.cookie.split(';');
	for(var i = 0; i < ca.length; i++) {
		var c = ca[i];
		while (c.charAt(0)==' ') {
			c = c.substring(1, c.length);
		}
		if (c.indexOf(nameEQ) == 0) 
			return c.substring(nameEQ.length, c.length);
	}
	return null;
}

function eraseCookie(cookieName) {
	setCookie(cookieName, '', -1);
}