// name =string equal to the name of the instance of the object
// defaultExpiration =number of units to make the default expiration date for the cookie
// expirationUnits ='seconds' | 'minutes' | 'hours' | 'days' | 'months' | 'years' (default is 'days')
// defaultDomain =string, default domain for cookies; default is current domain minus the server name
// defaultPath =string, default path for cookies; default is '/'
function Cookiemanager(name,defaultExpiration,expirationUnits,defaultDomain,defaultPath) {
	// remember our name
	this.name =name;
	// get the default expiration
	this.defaultExpiration =this.getExpiration(defaultExpiration,expirationUnits);
	// set the default domain to defaultDomain if supplied; if not, set it to document.domain
	// if document.domain is numeric, otherwise strip off the server name and use the remainder
	this.defaultDomain =(defaultDomain)?defaultDomain:(document.domain.search(/[a-zA-Z]/) ==-1)?document.domain:document.domain.substring(document.domain.indexOf('.') + 1,document.domain.length);
	// set the default path
	this.defaultPath =(defaultPath)?defaultPath:'/';
	// initialize an object to hold all the document's cookies
	this.cookies =new Object();
	// initialize an object to hold expiration dates for the doucment's cookies
	this.expiration =new Object();
	// initialize an object to hold domains for the doucment's cookies
	this.domain =new Object();
	// initialize an object to hold paths for the doucment's cookies
	this.path =new Object();
	// set an onlunload function to write the cookies
	window.onunload =new Function (this.name+'.setDocumentCookies();');
	// get the document's cookies
	this.getDocumentCookies();
	}
// gets an expiration date for a cookie as a GMT string
// expiration =integer expressing time in units (default is 7 days)
// units ='miliseconds' | 'seconds' | 'minutes' | 'hours' | 'days' | 'months' | 'years' (default is 'days') 
Cookiemanager.prototype.getExpiration =function(expiration,units) {
	// set default expiration time if it wasn't supplied
	expiration =(expiration)?expiration:7;
	// supply default units if units weren't supplied
	units =(units)?units:'days';
	// new date object we'll use to get the expiration time
	var date =new Date();
	// set expiration time according to units supplied
	switch(units) {
		case 'years':
			date.setFullYear(date.getFullYear() + expiration);
			break;
		case 'months':
			date.setMonth(date.getMonth() + expiration);
			break;
		case 'days':
			date.setTime(date.getTime()+(expiration*24*60*60*1000));
			break;
		case 'hours':
			date.setTime(date.getTime()+(expiration*60*60*1000));
			break;
		case 'minutes':
			date.setTime(date.getTime()+(expiration*60*1000));
			break;
		case 'seconds':
			date.setTime(date.getTime()+(expiration*1000));
			break;
		default:
			date.setTime(date.getTime()+expiration);
			break;
		}
	// return expiration as GMT string
	return date.toGMTString();
	}
// gets all document cookies and populates the .cookies property with them
Cookiemanager.prototype.getDocumentCookies =function() {
	var cookie,pair;
	// read the document's cookies into an array
	var cookies =document.cookie.split(';');
	// walk through each array element and extract the name and value into the cookies property
	var len =cookies.length;
	for(var i=0;i < len;i++) {
		cookie =cookies[i];
		// strip leading whitespace
		while (cookie.charAt(0)==' ') cookie =cookie.substring(1,cookie.length);
		// split name/value pair into an array
		pair =cookie.split('=');
		// use the cookie name as the property name and value as the value
		this.cookies[pair[0]] =pair[1];
		}
	}
// sets all document cookies
Cookiemanager.prototype.setDocumentCookies =function() {
	var expires ='';
	var cookies ='';
	var domain ='';
	var path ='';
	for(var name in this.cookies) {
		// see if there's a custom expiration for this cookie; if not use default
		expires =(this.expiration[name])?this.expiration[name]:this.defaultExpiration;
		// see if there's a custom path for this cookie; if not use default
		path =(this.path[name])?this.path[name]:this.defaultPath;
		// see if there's a custom domain for this cookie; if not use default
		domain =(this.domain[name])?this.domain[name]:this.defaultDomain;
		// add to cookie string
		cookies =name + '=' + this.cookies[name] + '; expires=' + expires + '; path=' + path + '; domain=' + domain;
		document.cookie =cookies;
		}
	return true;
	}
// gets cookie value
// cookieName =string, cookie name
Cookiemanager.prototype.getCookie =function(cookieName) {
	var cookie =this.cookies[cookieName]
	return (cookie)?cookie:false;
	}
// stores cookie value, expiration, domain and path
// cookieName =string, cookie name
// cookieValue =string, cookie value
// expiration =number of units in which the cookie should expire
// expirationUnits ='miliseconds' | 'seconds' | 'minutes' | 'hours' | 'days' | 'months' | 'years' (default is 'days')
// domain =string, domain for cookie
// path =string, path for cookie
Cookiemanager.prototype.setCookie =function(cookieName,cookieValue,expiration,expirationUnits,domain,path) {
	this.cookies[cookieName] =cookieValue;
	// set the expiration if it was supplied 
	if (expiration) this.expiration[cookieName] =this.getExpiration(expiration,expirationUnits);
	// set path if it was supplied
	if (domain) this.domain[cookieName] =domain;
	if (path) this.path[cookieName] =path;
	return true;
	}
var cookieManager =new Cookiemanager('cookieManager',1,'years');