Help with House trading. The invite button is grayed out.

[Trialsking]

I am trying to do and house crafting trade with someone who was nice enough to offer their crafting services.  I have been accepted into their house and can see all members so I assume am now a member.  He gave me his name to invite to trade.  When I enter it into the "Invite player to trade" screen, the button that says "Invite" is still grayed out and will not respond.  I have tried several others members names  with no effect.  Basically I cannot invite anyone to trade with in the house. 

What am I doing wrong?  I am not a full member?  Is there something else I need to do on my end?  Sorry for being a noob, but this is my first time in a house and it was really only for crafting, and no one walked me through the steps.

Thanks