You don't have to 'add a script' to make the era tileset work. Just logon era while you're on graal pc, go to start>instal Packages>Era Development Kit.
Then go to your Graal Editor>open>Graal folder>levels>era development kit>era_tileset (open this) Then go to you're editor again Open blank level > save as era_(namehere).nw
then you're all set.