Hi
My airline is based in IST/Turkey and my HUB is IST. An airline based in IST too filled (I didn't understand how the airline achieved) the slots so early in the game and dominated IST. So I want to change my base. If I move my flights to another airport in the same country will there be any disadvantages for me because the new airport is not my HUB. I mean I want to ask are there any advantages of the airport which is my HUB in my airline info page.
Besim
If the new airport is within the same country then it will have no effect on you at all
Basically it dosent matter where your Headquarters are. If you live in Van or Antalya, and wants your headquarters in that city - just do that. You can still operate out of IST.
The HUB does not refer to where you initially locate your company. A HUB is an airport, where you place tons of airplanes, and have thousands of departures.
If you take a look, at older servers - you will see companies in Europe with HUBS at both LHR, AMS, FRA, CDG and so on.
Hope you get my point 
Thank you for fast replies :)
And being you if your flights get full loads at IST, do not cancel them. Just start operating other flights from other airports in Turkey.
Since I an based at IST as well, feel free to move your flights 
When you first create an airline, it asks you to choose a Headquarters. I think this is what you meant to say when you said Hub. In real life, the headquarters is only where all of the corporate officials work. As someone said before, a Hub is just a large airport where an Airline stations a lot of it's fleet and has a lot of routes into/out of. Commonly, the headquarters is close to the airline's biggest hub, which is the case with United Airlines (HQ and largest Hub are at Chicago O'Hare.) However, this is not always the case. If you are operating with a hub/spoke system (all of your routes either begin or end with a central airport,) your hub can be anywhere. It doesn't even have to be in the same country as your HQ (United has a Hub in Guam and Tokyo.) Hope this helps!
The HQ in AS defines what traffic rights you have. You may of course operate from other hubs but within the confines of the traffic rights that your HQ defines