// Hash creation and initialization
var hash = new Object;
var hash = {};
var hash = { foo: "Foo!", bar: "Bar!" };
var hash = { "spaced out": "ok" };

// Setting
hash.foo    = "Foo!";  // Static key
hash["bar"] = "Bar!";  // Dynamic key

// Getting
alert("hash.foo: " + hash["foo"]);  // Dynamic key
alert("hash.bar: " + hash.bar);     // Static key

// Iterating
for (var key in hash) {
   var val = hash[key];
   alert("hash." + key + ": " + val);
}