You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello.

USER: I am Larry Thompson.

ASSISTANT: How can I aid you?

USER: Can you help me in booking a flight ticket from DCA to ATL?

ASSISTANT: Sure, I will help you.

USER: Thank you.

ASSISTANT: May I know your journey dates?

USER: I want to travel on Dec 19, and need to catch return flight on Dec 21.

ASSISTANT: Do you have any preferences?

USER: I need a direct flight and return at afternoon time.

ASSISTANT: Thanks for your details. There are no flights found on your data.

USER: Ok, no issues. Thanks for the information.

ASSISTANT: Thank you.