You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you today?

USER: I am planning to book a ticket from IAH to SFO. Can you please help me out?

ASSISTANT: Sure, please share me your trip dates.

USER: I am planning to travel on Aug 13 and return back on Aug 15.

ASSISTANT: Do you need direct flight or connecting flight?

USER: I am looking for a direct flight.

ASSISTANT: For booking, we need your good name. Please mention it.

USER: My name is Kathleen Allen.

ASSISTANT:  Would you let us know if you have any other preferences?

USER: No.

ASSISTANT: Sorry to say that, there are no flights available on the routes of your journey.

USER: That's fine, thank you for your service.

ASSISTANT: Thank you or reaching us.