You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

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

ASSISTANT: Let me know the travel dates please?

USER: My travel dates are Feb 26 and Feb 28.

ASSISTANT: Is there any connection limit?

USER: No.

ASSISTANT: Is there any class preference?

USER: I prefer economy class.

ASSISTANT: Are there any more preferences?

USER: I would like to return back in the afternoon time.

ASSISTANT: May I know your name please?

USER: My name is Nancy Martinez.

ASSISTANT:  Nancy Martinez, I regret to inform that there are no flights on your route with the given dates.

USER: No issues, thank you for the information.

ASSISTANT: Thank you for reaching us.