You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I aid you?

USER: Can you please help me in booking my ticket from DEN to SFO?

ASSISTANT: Can I have your travelling dates?

USER: My travelling dates are from 10/18 to 10/20.

ASSISTANT: May I know your connection limit?

USER: Yes, I need a single connecting flight.

ASSISTANT: Please help me with your name to proceed further.

USER: Myself Patrick Hall.

ASSISTANT:  Sorry to say, there are no flights which travels to your region on your planned dates of journey due to heavy bookings.

USER: It's ok, no issue. Thank you for your help.

ASSISTANT: Welcome Patrick Hall.