You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Carolyn Anderson.

ASSISTANT: Is there any help that you need from our agency?

USER: Can you please assist me to search the flight from Oakland to Phoenix?

ASSISTANT: Sure, I am your agent to help you today.

USER: Thank you.

ASSISTANT: May I know your preferable travel dates?

USER: My preferable travel dates are Apr 26 and Apr 28.

ASSISTANT: May I know your respective airport codes?

USER: The boarding and landing airport codes are OAK and PHX.

ASSISTANT: Which class that you need?

USER: I am fine with any class.

ASSISTANT: I am sorry to say that no flight is moving to your region to book the ticket.

USER: It's ok, not a problem with that. Thank you for your help.

ASSISTANT: You are most welcome.