So I've read what seems like a million help areas to figure out how to make the trade work, but every time I try to do it, it never works.

I'm trying to trade between gold and silver on TGB, but when I try to open silver, for example, on the second screen, the saved file isn't there. I tried doing the filename change to ".sa2" or whatever, but every time I try to open it - it comes up with an error message, so I don't know if I'm moving files the wrong way or what.

Can someone give me a careful explanation how to do this? Thanks.