You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you today?

USER: I am Jerry Edwards. I want to book a ticket from EWR to IAD, Can you help me for booking my ticket?

ASSISTANT: Sure, may I know your planned travel dates?

USER: My travelling dates are on Mar 20 and Mar 22.

ASSISTANT: Please allow me a moment.

USER: Sure.

ASSISTANT: Regret to inform you that, no airlines is providing a flight on your dates to book a ticket.

USER: Ok, no problem. Thank you for informing me.

ASSISTANT: You are most welcome and next time we can serve you better.