help in writing Script to check if empire has Facility

I need help,

What im attempting to do is have a script check to see if an empire has a specific facility or not.

If the empire has said facility then the empire would gain an ability

Script looks for =
Fusion Research Facility

If found
Race gains Tech = Fusion

so Tech's that require
Fusion = 1

Can now be researched

And so on. But I can't seam to be able to have the script set the tech.

Thanks

Edit - Changed Subject to more accurately reflect question.