What is the right syntax of using Element#observe for the click event?

Method "on()" of Event class can be used to set up event handlers, with or without event delegation. What is not true about Event.on?

Which callback takes precedence: on<HTTP RESPONSE CODE>, onFailure, or onSuccess?

What property stores the active Ajax requests?

To use JSON with AJAX, what must be invoked on the transport's responseText property?

DOM methods are mostly encapsulated by what object?

Which four utilities does Prototype use?

How would you remove a class named 'removeclass' from an element?

What object is used to parse JSON?

(42).toPaddedString(4) returns what?

Evaluate the following statement: Hash is a set of key/value pairs with Element.Layout subclass. For convenience a developer can use #H() alias.