/**
 * This is the Cookie() constructor function.
 *
 * This constructor looks for a cookie with the specified name for the
 * current document.  If one exists, it parses its value into a set of
 * name/value pairs and stores those values as properties of the newly created
 * object.
 *
 * To store new data in the cookie, simply set properties of the Cookie
 * object.  Avoid properties named "store" and "remove" since these are 
 * reserved as method names.
 * 
 * To save cookie data in the web browser's local store, call store().
 * To remove cookie data from the browser's store, call remove().
 *
 * The static method Cookie.enabled() returns true if cookies are
 * enabled and returns false otherwise.
 */
function Cookie(name) {
    this.$name = name;  // Remember the name of this cookie
	this.value = null;
    // First, get a list of all cookies that pertain to this document
    // We do this by reading the magic Document.cookie property
    // If there are no cookies, we don't have anything to do 
    var allcookies = document.cookie;
    if (allcookies == "") return;

    // Break the string of all cookies into individual cookie strings
    // Then loop through the cookie strings, looking for our name
    var cookies = allcookies.split(';');
    var cookie = null;
	var temp = null;
    for(var i = 0; i < cookies.length; i++) {
		temp = (cookies[i] || "").replace( /^\s+|\s+$/g, "" );
        // Does this cookie string begin with the name we want?
        if (temp.substring(0, name.length+1) == (name + "=")) {
            cookie = temp;
            break;
        }
    }

    // If we didn't find a matching cookie, quit now
    if (cookie == null) return;

    // The cookie value is the part after the equals sign
    var cookieval = cookie.substring(name.length+1);

	this.value = decodeURIComponent(cookieval);
    
}

/**
 * This function is the store() method of the Cookie object.
 *
 * Arguments:
 *
 *   daysToLive: the lifetime of the cookie, in days. If you set this
 *     to zero, the cookie will be deleted.  If you set it to null, or 
 *     omit this argument, the cookie will be a session cookie and will
 *     not be retained when the browser exits.  This argument is used to
 *     set the max-age attribute of the cookie.
 *   path: the value of the path attribute of the cookie
 *   domain: the value of the domain attribute of the cookie
 *   secure: if true, the secure attribute of the cookie will be set
 */
Cookie.prototype.store = function(daysToLive, path, domain, secure) {
	
	if(this.value === null ) return;
	
   var cookie = this.$name + '=' + encodeURIComponent(this.value);
    
    if (daysToLive || daysToLive == 0) { 
        cookie += "; max-age=" + (daysToLive*24*60*60);
		var date = new Date();
		date.setTime(date.getTime() + daysToLive*24*60*60*1000);
		cookie += "; expires="  + date.toGMTString();
    }

    if (path) cookie += "; path=" + path;
    if (domain) cookie += "; domain=" + domain;
    if (secure) cookie += "; secure";

    // Now store the cookie by setting the magic Document.cookie property
	
    document.cookie = cookie;
}

Cookie.prototype.setValue = function(value) {
   this.value = value;
   
}

Cookie.prototype.getValue = function() {
   return this.value;
   
}

/**
 * This function is the remove() method of the Cookie object; it deletes the
 * properties of the object and removes the cookie from the browser's 
 * local store.
 * 
 * The arguments to this function are all optional, but to remove a cookie
 * you must pass the same values you passed to store().
 */
Cookie.prototype.remove = function(path, domain, secure) {
    // Delete the properties of the cookie
    for(var prop in this) {
        if (prop.charAt(0) != '$' && typeof this[prop] != 'function') 
            delete this[prop];
    }

    // Then, store the cookie with a lifetime of 0
    this.store(0, path, domain, secure);
}

/**
 * This static method attempts to determine whether cookies are enabled.
 * It returns true if they appear to be enabled and false otherwise.
 * A return value of true does not guarantee that cookies actually persist.
 * Nonpersistent session cookies may still work even if this method 
 * returns false.
 */
Cookie.enabled = function() {
    // Use navigator.cookieEnabled if this browser defines it
    if (navigator.cookieEnabled != undefined) return navigator.cookieEnabled;

    // If we've already cached a value, use that value
    if (Cookie.enabled.cache != undefined) return Cookie.enabled.cache;

    // Otherwise, create a test cookie with a lifetime
    document.cookie = "testcookie=test; max-age=10000";  // Set cookie

    // Now see if that cookie was saved
    var cookies = document.cookie;
    if (cookies.indexOf("testcookie=test") == -1) {
        // The cookie was not saved
        return Cookie.enabled.cache = false;
    }
    else {
        // Cookie was saved, so we've got to delete it before returning
        document.cookie = "testcookie=test; max-age=0";  // Delete cookie
        return Cookie.enabled.cache = true;
    }
}