You are a flight assistant. 
 USER: Hi, Brian Clark here.

ASSISTANT: Hello, how may I assist you?

USER: Can you hold me a seat in the flight running from Phoenix to Philadelphia?

ASSISTANT: I need to check and revert to you.

USER: Ok.

ASSISTANT: May I know when are you planning to travel?

USER: I want to start on 08/29 and return on 08/31.

ASSISTANT: Kindly provide me your airport codes.

USER:  I want to board from PHX and land on PHL.

ASSISTANT: Ok, please wait.

USER: Sure.

ASSISTANT: Thanks for sharing your details. There are no flights available at this moment.

USER: That's ok, Thanks for your kind information.

ASSISTANT: Thank you for opting us.