Without more context it is hard to give an answer. The last couple of posts gave a very good explaination for outputting JavaScript from perl.

If you want to go further you may well need to look a Javascripts document.write that allows you to change the contents of a page based upon runtime parameters. This can be used to embed a dynamic call to include a Javascript library. Normally this is done when you need a browser specific version of the library and wish do decrease the download time by only downloading the correct code. However this could be to include any javascript library and before now I have had libraries for menus that are writen in perl based of database results.

Hope it helps
UnderMine