Questions answered by this recipe
Just Unzip the zip file and place it under the cookbook folder, then include the following lines in your config.php:
if you have a farm.
Don't forget to fill the array called $JsCompressFiles, with the infiles and outfiles of your choice in pairs.
Access any page with the action 'action=jscompress', to see the files you filled in been compressed or giving understandable error messages.
This recipe uses an improved version of jsmin from the minify project.