Thanks, for all your help. I did get through to a dealer and they contacted the mfg and they no longer make the round 4 pin plug. They said I have to convert to the standard 7 pin round plug, so I'll go talk to my RV guy.
Thanks again for the warm welcome.
P.S. This weekend, we will be staying for the first time in an RV Park. All this RV stuff is brand new and exciting.