How do you get to customize which airline your plane can be on flight simulator?

I've seen pictures of people who use flight simulator and have real world airlines(Virgin, Delta, Lufthansa...) and was wondering how I can get that for my game.How do you get to customize which airline your plane can be on flight simulator?
i believe there are certain sites online that provide colour schemes and new planes for download, but these cost about half as much individually as the game in full.How do you get to customize which airline your plane can be on flight simulator?
Like the sites PAA727 %26amp; Cameron Said. *Note you must join to down load but it's free.



But I have a feeling your going to need help Later on.



FSXNWA@yahoogroups.com Has a Photo page with step by step how to upload your new Skin's aka Textures and or full model.



If you want to fill your skies with real world airlines

Join Flightsim.com then go to World of AI.com and down load the installer and all the Real world airlines you want. Blue skies and Happy Contrails to you.How do you get to customize which airline your plane can be on flight simulator?
You can download different paint schemes and complete aircraft from sites such as:



http://flightsim.com/home.htm

http://avsim.com/

http://www.simviation.com/menu.html

http://www.fsdownload.com/
You can download paint schemes from many sites the best being simviation.com