function setCookie(name, value, expire ){
	document.cookie = name + "=" + escape(value) + ((expire==null ? "":(";expires=" + expire.toGMTString())));
}
	   
function getExpireDate(days){
	var expires = new Date();
	expires.setTime((new Date().getTime() + days*24*60*60*1000));
	return expires;
}
	   
function getCookie(Name) {
	var search = Name + "="
	if (document.cookie.length > 0) { // if there are any cookies
		offset = document.cookie.indexOf(search)
		if (offset != -1) { // if cookie exists
			offset += search.length
			// set index of beginning of value
			end = document.cookie.indexOf(";", offset)
			// set index of end of cookie value
			if (end == -1)
				end = document.cookie.length
			return unescape(document.cookie.substring(offset, end))
		}else{
			return null;
		}
	}
}

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