You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I assist you today?

USER: I want to book a ticket from PHX to JFK. Could you book a ticket?

ASSISTANT: Sure, please provide me your travelling dates.

USER: Travelling dates are from June, 20 to June, 22.

ASSISTANT: May I know your name to proceed further?

USER: I am Kevin Green.

ASSISTANT: Sorry, I could not find any flight with your travelling dates.

USER: Thank you.

ASSISTANT: My pleasure.