Is the avian flu a foodborne illness or how do you catch it?

No, airborne: It is transmitted through contamination of air. Transmission from birds to humans requires close contact with infected birds. Properly cooked chicken meat does not transmit bird flu.

Same as regular flu: Not really - flu is usually transmitted person to person through aerosolized droplets (a cough or sneeze does this well) that land in the upper respiratory tract or mucus membranes. Of note flu can last on surfaces for quite a while so decontaminating surfaces around infected folk is important to prevent transmission.