You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: I am looking for a flight from SEA to OAK, can you help me in booking?

ASSISTANT: Sure, may I know your trip dates please?

USER: Sure, my planned travel dates are Jan 29 and Jan 31.

ASSISTANT: Do you have any other requirements?

USER: Yes, I mostly for a normal-cost airlines.

ASSISTANT: Can I know your name please?

USER: Myself Kevin Williams.

ASSISTANT: Sorry, we regret to inform you that there is no flight available as per your request.

USER: That's ok, no problem. Thank you for the information.

ASSISTANT: Most welcome.