You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello,.

USER: I am Paul Lee.

ASSISTANT: How can I aid you?

USER: Please book a flight ticket from Phoenix, PHX to Philadelphia, PHL.

ASSISTANT: Sure, on what dates you wish to travel?

USER: My travelling dates are from 04/21 to 04/23.

ASSISTANT: Do you need any other requirements to be met?

USER: I need a direct flight.

ASSISTANT: Please hold on, I will revert to you.

USER: Sure.

ASSISTANT: Thanks for being on hold, there were no flights available with your given details.

USER: Ok, No issues. Thank you.

ASSISTANT: Thanks for connecting with us.