You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Samuel Nelson here.

ASSISTANT: How can I help you at this moment?

USER: I need your help in booking of a flight ticket from HOU to SFO for an important business meeting, can you please help me out with booking of a flight ticket on those locations?

ASSISTANT: Sure, I am happy to help you in booking flight ticket.

USER: Thank you.

ASSISTANT: Can you please mention your travel dates for booking flight ticket?

USER: Sure, I am planning to move on 11/11 and please book my return ticket on 11/13.

ASSISTANT: May I know your preferable airport code names for further process?

USER: Sure, I want to travel from HOU to SFO.

ASSISTANT: Please hold on a moment, I will check flight availability in this route.

USER: Ok, take your time.

ASSISTANT: Sorry for the inconvenience no flights available in this route as per your requested dates.

USER: Oh! So sad to hear that. Ok, I will go with another airline. Thank you for your service.

ASSISTANT: You are welcome.