JavaScript is a good idea, but due to implementations of certain functions and the inclusion of certain API calls - it can be more trouble than it is worth. A lot of people have now removed JavaScript support so that their browsers do not process these embedded instructions

Scripts that I have written include:

An advanced rollover script that will not only change the image - but implements a third state - selected, so you dont have to reload the frame that contains the image to indicate current location. Oh, and it will also allow the update of a 'descriptive' image or text fragment elsewhere in the document.

A one line jump script - select from the drop-down and go there immediately

Position the cursor in a form field ready to accept the user input - makes your forms friendlier!