
Expansion of the object's properties
All objects now react as if the expando property were set to true. However, the expando property is not been implemented.
This means that all objects can now have user-defined properties added to them. Therefore, any reference to an unknown property for an object will create that property should it not already exist for that object. This means that care is required with upper and lowercase letters in properties. For example, innerhtml will not be the same property as innerHTML. Also the effect of object.expando=false will create or set a user-defined property that is named expando.