storage.js

var storage = {};
if (window.localStorage)
{
	storage.get = function(name)
	{
		if (window.localStorage[name] === undefined)
		{
			return undefined;
		}
		return JSON.parse(window.localStorage[name]);
	}

	storage.set = function(name, data)
	{
		window.localStorage[name] = JSON.stringify(data);
	}

	storage.rem = function(name)
	{
		delete window.localStorage[name];
	}

	storage.is = function(name)
	{
		return !(window.localStorage[name] === undefined);
	}
}
else
{
	storage.get = function(name)
	{
		var i, cookies, cookie
		name = name + '=';
		cookies = document.cookie.split(';');
		for (i = 0; i < cookies.length; i++)
		{
			while (cookies[i].slice(0, 1) === ' ')
			{
				cookies[i] = cookies[i].slice(1);
			}
			if (cookies[i].indexOf(name) === 0)
			{
				return JSON.parse(cookies[i].slice(name.length));
			}
		}
		return undefined;
	}

	storage.set = function(name, data)
	{
		var date = new Date();
		date.setTime(date.getTime() + 2592000000);
		var expires = '; expires=' + date.toGMTString();

		data = JSON.stringify(data);

		document.cookie = name + '=' + data + expires + '; path=/';
	}

	storage.rem = function(name)
	{
		var date = new Date();
		date.setTime(date.getTime() - 1);
		var expires = date.toGMTString();

		document.cookie = name + '= ; expires=' + expires + '; path=/';
	}

	storage.is = function(name)
	{
		return !(storage.get(name) === undefined);
	}
}