function readCookie(name) {
	var nameEQ = name + "=";
	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(name) {
	createCookie(name,"",-1);
}
function createCookie(name,value,days) {
	if (days) {
		var date = new Date();
		date.setTime(date.getTime()+(days*24*60*60*1000));
		var expires = "; expires="+date.toGMTString();
	}
	else var expires = "";
	document.cookie = name+"="+value+expires+"; path=/;domain=.exploratorium.edu";
}

function testSessionCookie () { 
	document.cookie ="testSessionCookie=Enabled"; 
	if (getCookieValue ("testSessionCookie")=="Enabled") 
		return true  
	else 
		return false; 
	} 

function sessionCookieTest() { 
	if (!testSessionCookie()) 
	alert("Cookies are disabled in your browser. Please enable cookies to prevent having to fill out this form for each document you download.");
}  

function getCookieValue (cookieName) { 
	var exp = new RegExp (escape(cookieName) + "=([^;]+)"); 
	if (exp.test (document.cookie + ";")) { 
		exp.exec (document.cookie + ";"); 
		return unescape(RegExp.$1); 
	} 
		else return false; 
}