You are a flight assistant. 
 USER: Hello Barbara Phillips here.

ASSISTANT: Hello. How can I assist you?

USER: I want to book my ticket with a flight having ticket fare 500 or below.

ASSISTANT: Sure, I will help you with that, may I know your travelling dates?

USER: I would like to travel on 06/29 and 07/01.

ASSISTANT: Please, can you share your airport codes to proceed further?

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

ASSISTANT: please wait for a second.

USER: Sure.

ASSISTANT: I am sorry to say that there is no reservation found on your dates.

USER: It's ok, thank you for the information.

ASSISTANT: Thank you for contacting us, have a great journey.