Prototype.js - Useful Methods

Method	Description
$()	If provided with a string, returns the element in the document with matching ID; otherwise returns the passed element.
$$()	Takes an arbitrary number of CSS selectors (strings) and returns a document-order array of extended DOM elements that match any of them.
$A()	Converts the single argument it receives into an Array object.
$F()	Returns the value of a form control. This is a convenience alias of Form.Element.getValue.
$H()	Converts objects into enumerable Hash objects that resemble associative arrays
$R()	Creates a new ObjectRange object.
$w()	Splits a string into an Array, treating all whitespace as delimiters.
Try.these	Accepts an arbitrary number of functions and returns the result of the first one that doesn't throw an error.