// Cookie functions from "JavaScript: The Definitive Guide, Third Edition"
//  by David Flanagan Copyright © 1996, 1997, 1998 O'Reilly & Associates

// The constructor function: creates a cookie object for the specified
// document, with a specified name and optional attributes.
// Arguments:
//   document: The Document object that the cookie is stored for. Required.
//   name:     A string that specifies a name for the cookie. Required.
//   hours:    An optional number that specifies the number of hours from now
//             that the cookie should expire.
//   path:     An optional string that specifies the cookie path attribute.
//   domain:   An optional string that specifies the cookie domain attribute.
//   secure:   An optional Boolean value that, if true, requests a secure cookie.
//
function Cookie(document, name, hours, path, domain, secure)
{
    this.$document = document;
    this.$name = name;
    if (hours)
        this.$expiration = new Date((new Date()).getTime() + hours*3600000);
    else this.$expiration = null;
    if (path) this.$path = path; else this.$path = null;
    if (domain) this.$domain = domain; else this.$domain = null;
    if (secure) this.$secure = true; else this.$secure = false;
}

function _Cookie_store()
{
    var cookieval = "";
    for(var prop in this) {
        if ((prop.charAt(0) == '$') || ((typeof this[prop]) == 'function')) 
            continue;
        if (cookieval != "") cookieval += '&';
        cookieval += prop + ':' + escape(this[prop]);
    }
    var cookie = this.$name + '=' + cookieval;
    if (this.$expiration)
        cookie += '; expires=' + this.$expiration.toGMTString();
    if (this.$path) cookie += '; path=' + this.$path;
    if (this.$domain) cookie += '; domain=' + this.$domain;
    if (this.$secure) cookie += '; secure';
    this.$document.cookie = cookie;
}

function _Cookie_load()
{
    var allcookies = this.$document.cookie;
    if (allcookies == "") return false;

    var start = allcookies.indexOf(this.$name + '=');
    if (start == -1) return false;   // Cookie not defined for this page.
    start += this.$name.length + 1;  // Skip name and equals sign.
    var end = allcookies.indexOf(';', start);
    if (end == -1) end = allcookies.length;
    var cookieval = allcookies.substring(start, end);

    var a = cookieval.split('&');    // Break it into array of name/value pairs.
    for(var i=0; i < a.length; i++)  // Break each pair into an array.
        a[i] = a[i].split(':');

    for(var i = 0; i < a.length; i++) {
        this[a[i][0]] = unescape(a[i][1]);
    }

    return true;
}

function _Cookie_remove()
{
    var cookie;
    cookie = this.$name + '=';
    if (this.$path) cookie += '; path=' + this.$path;
    if (this.$domain) cookie += '; domain=' + this.$domain;
    cookie += '; expires=Fri, 02-Jan-1970 00:00:00 GMT';

    this.$document.cookie = cookie;
}

new Cookie();
Cookie.prototype.store = _Cookie_store;
Cookie.prototype.load = _Cookie_load;
Cookie.prototype.remove = _Cookie_remove;