You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you?

USER: I am Elizabeth Campbell. Can you please book a flight ticket from LGA to DCA?

ASSISTANT: Sure, may I know your travel dates?

USER: Sure, I need to travel on dates of Feb 01 and Feb 03.

ASSISTANT: At what time do you like to travel?

USER: I would like to return in afternoon time.

ASSISTANT: Sorry, there is no flight on your route.

USER: Oh! It is sad to hear. Anyway, thank you for your time.

ASSISTANT: Thank you.