What to ask at an open house?

Please give advice on the must-ask questions at an open house.

TIA!!!

Ok we just went through the open house process and now are in contract so here is what we asked...

-How old is the house?
-If there are any extensions, ask if the seller has a Certificate of Occupancy for them
-Gas or Oil?
-How old is the roof and windows?
-How old are the appliances?
-How many days has the home been on the market? (sometimes they will tell you, but if not, have your real estate agent check into it for you if its a concern...it will give you leverage when putting in a bid)

Im sure after you go to a few of these, you will come up with your own questions, but these were the ones I always asked when looking.

Also, some advice...
go to as many open houses as you can, even if you are mildly interested in the house. You will get a better idea of what you want and even some ideas on remodeling when you find your dream home. Like I said before, FH and I are in contract and learning as we go along, so if you have any questions, feel free to ask