Encytemedia has a tutorial up on their site that shows developers how to handle events with the Prototype library. The tutorial shows lots of examples in code. From the article:

Events drive interaction for almost everything and the web is no exception. In the style of my last article on Prototype, lets take a code-heavy look at how Prototype lets us work with events.Here is a link to the article.

Reference link to Ajaxian where I initially read about this post.Link to Sam Stephenson's Prototype site where I got the image for this story and where you can get Prototype.