// 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');