You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you for today?

USER: I am William Garcia. I am planning to book a ticket from ATL to DFW. Can you please help me out to book a ticket for me?

ASSISTANT: Yes, could you tell me your dates of travel?

USER: These are my travelling dates 04/18 and return back on 04/20.

ASSISTANT: Give me a moment.

USER: Sure.

ASSISTANT: Sorry to inform you that there are no flights found on your requirement.

USER: That's fine.

ASSISTANT: Thank you for contacting us.

USER: Thank you for your service.