Anybody handy with Filemaker?

[Desmo]

I'm trying to get something working in Filemaker Pro 12 and can't quite get it working. I have a list of suppliers and an estimates sheet. All I'm trying to get is, at the bottom of the estimates sheet, about 5 dropdown boxes that I will be able to select from a list of suppliers and then next to each dropdown box another field will show their email address. I'll then add a further button that will email the job spec to the selected supplier.

I can get it working if I just have one dropdown box so it shows the email address for the one selected supplier but if I try more than one I just can't get it working.