You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: Margaret Wright here. Can you please reserve a flight ticket from EWR to ATL?

ASSISTANT: Sure, I am here to help you in ticket booking. May I know your dates?

USER: Sure, I am planning to move on 12/19 and please book my return ticket on 12/21.

ASSISTANT: I am sorry there are no flight that are moving on your dates.

USER: Oh! So sad to hear that. Anyway, thank you for the information.

ASSISTANT: Thank you for reaching us, have a nice day.

USER: Welcome.