You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you for the day?

USER: I am Jonathan Williams, want to travel from DCA to EWR. Please help me in booking my ticket.

ASSISTANT: Sure, I will help you with that. Can you please share me your preferable journey dates?

USER: My travelling dates are from 11/02 to 11/04.

ASSISTANT:  Please wait for a moment, I will get back with your flight details.

USER: Sure.

ASSISTANT: Sorry to tell you, there are no flights found as per your travelling dates.

USER: It's ok, thank you.

ASSISTANT: Thank you for approaching us, have a great day.

USER: Thank you.