Question - Reusable Header and Footer code

I am trying to following the instructions for creating report header and footer that is reusable from the following tutorial: 

http://www.ariscommunity.com/users/volker-eckardt/2010-05-18-aris-scripting-tutorial-part-7-reusable-code-and-common-header-and-footer

I have the .js file saved in the Common files group and have imported this file into our custom category created for our company, but when I go into a report and select the properties, the box that says "Imported files" is gray and not allowing me to click on it.  Any ideas?  We are in admin module.  Is there something else we need to do to make the code available before we can import it into another report?  I notice that when we go into one of the standard category reports and look at the properties, the box is NOT grayed out, and my .js file DOES show in the list of available files.    However, if we create a new report in this category, the box IS grayed out.  Is there another step we are missing here to make the .js file available?  Please help:)

Thanks.