Using Element.Layout you can measure elements that are hidden:

Which method that is not available to convert to JSON in Prototype

How would you create an AJAX call to get the url '/echomyid'?

What object would you use in Prototype, and what are the benefits of using said object?

How can you get a copy of the array without any null or undefined values?

The code: var json = transport.responseText.evalJSON(true); will check for what?

How would you wait for the DOM to be loaded so that you can start manipulating the page with Javascript?

What code will return an instance of Element.Layout?

Which of the following is not an example of an AJAX callback?

How can you inherit from a Storage class?

Element#on has what distinct and beneficial features in Prototype 1.7?