You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I aid you?

USER: I am Thomas Thomas. I need a direct flight to attend a client meeting in Phoenix, so please book a flight ticket from New York.

ASSISTANT: Sure, may I know your planned travel dates to check for the flight availability?

USER: I want to fly on May 31, return on June 02.

ASSISTANT: May I know your respective airport codes?

USER: My source and destination airport codes are EWR and PHX.

ASSISTANT: Do you have any specifications?

USER: Please make sure that my return time is afternoon.

ASSISTANT: Sorry, there are no flights available for your desired dates.

USER: No problem, thank you.

ASSISTANT: Thank you for reaching us.