You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

USER: Can you please  book a flight ticket from IAD to LAX?

ASSISTANT: Sure, please help me with your journey dates.

USER: Thank you. I have planned my travel  dates as Sept 09 and Sept 11.

ASSISTANT: Ok, Do you have any class preference?

USER: No, I am ok with any class.

ASSISTANT: Ok, May I know your connection limit?

USER: I am looking for single connecting flight.

ASSISTANT: Ok, Is there any other preferences?

USER: No, I do not have any other specifications.

ASSISTANT: Thank you for providing details, we did not find any flights with your given details.

USER: Oh! It is sad to hear. Anyway, thank you for  your time.

ASSISTANT: May I know your name?

USER: Sure, myself Debra Carter.

ASSISTANT: Thank you for choosing us.

USER: Most welcome.