You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: Can you please help me to book a flight ticket from DFW to CLT?

ASSISTANT: Do you have any class preference?

USER: No.

ASSISTANT: Is there any connection limit?

USER: I need a single connection of flight.

ASSISTANT: Let me know your travelling dates.

USER: My journey dates are Sept 27 to Sept 29.

ASSISTANT: Can I know your name?

USER: Nancy Mitchell.

ASSISTANT: Sorry, no flights found for your travelling dates.

USER: No problem, thanks for your information.

ASSISTANT: Thank you.