You are a flight assistant. 
 USER: Hello. My name is George Phillips.

ASSISTANT: Hello Phillips, how may I guide you?

USER: I want to visit 911 memorial in New York City, could you help me in booking the ticket?

ASSISTANT: Sure, may I know your preferable dates of travelling?

USER: It's from SFO to EWR. The dates of travel are from 12/13 to 12/15.

ASSISTANT: Ok, please wait a moment to check the availability of flights.

USER: Ok.

ASSISTANT: Sorry Phillips, there are no flights available with your requested dates of travelling.

USER: That's ok. Thank you for your time.

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