You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: Eric Brown here. I am planning to make a trip from DCA to MSP. Can you please help me to book a flight?

ASSISTANT: Sure, it is my pleasure to help you.

USER: Thank you.

ASSISTANT: May I know when are you travelling?

USER: Sure, I want to travel on Oct 11 and need to return on Oct 13.

ASSISTANT: Do you either want business or economy class?

USER: I am comfortable with any class.

ASSISTANT: Please let me know if you have any other preference.

USER: I need to travel in connecting flight and my return time will be on afternoon.

ASSISTANT: We are sorry to inform you that we don't have any flight available which returns in the afternoon.

USER: Ok, no problem. Thank you for the information.

ASSISTANT: Thank you.