A simple implementation of a class pattern for Javascript

Class.js

  var Class = function (superClass, prototype) {
    if (prototype === undefined) {
      prototype = superClass;
    } else {
      var newPrototype = Object.create(superClass);
      for (var a in prototype) {
        newPrototype[a] = prototype[a];
      }
      prototype = newPrototype;
    }
    var ClassObject = function () {
      var obj = Object.create(prototype);
      obj.constructor.apply(obj, arguments);
      return obj;
    };
    ClassObject.prototype = prototype;
    return ClassObject;
  };

  // Usage:
  var Person = Class({
    constructor: function (name) {
      this.name = name;
    }
  });