Prototype-Overlay 0.1.0 
Simple utility allowing to show content inside an overlay window.
Copyright 2008 Tomasz Szymczyszyn
Licensed under new BSD license (see overlay.js for details)

For basic usage see project page at http://code.google.com/p/prototype-overlay.

Notes:

The overlay and its background may have arbitrary CSS classes assigned
with <code>cls</code> and <code>bckg_cls</code> options respectively. Some
of the CSS properties set with these classes may however be overriden by the script,
especially when animations are involved. The following should not be set
with arbitrary CSS:

 - z-index
 - opacity
 - position
 - dimensions of the background
 
These properties are set dynamically and setting them with CSS classes will
have no effect or may break the script.

Overlay allows for attaching custom event handlers:

 - before showing the window
 - after showing the window
 - after hiding the window

If overlay is animated events are fired before animation starts and after it ends.
These event hooks should not be used to implement custom animations (which may not
work as expected).
 
