Newbie Question: Double entry and imported data

[Andrew Grafham]

I've imported two OFX files into GnuCash, one for my bank account and
one for my credit card. There's a payment into the credit card account
from my bank account. At the moment they are two seperate
transactions. How can I tell GnuCash that they are two sides of the
same double entry?

Cheers

Andy