sessionStorage wrapper

domstorage.js

// Data stored in DOM Session Storage (on supported browsers).
// create the SessionObject with a unique key name, then put data
// in to the data property. It will be JSONified to and fro automatically
// between page loads.
var SessionObject = function(key) {
	this.data = null;
	this.key = key;
	this.store = window.sessionStorage;
	if (this.store[this.key])
	{
		this.data = (""+this.store[this.key]).evalJSON();
	}
	Element.observe(window, 'beforeunload', function(){
		this.store[this.key] = this.data.toJSON();		
	}.bind(this));
};
SessionObject.isSupported = function() {
	return (!!window.sessionStorage);	
};

//Example

var cart = new SessionObject('ShoppingCart');
cart.data = cart.data || [];
cart.data.push({id:1234, name:'Sweet Cuppin Cakes'});