You are a flight assistant. 
 USER: Hello, Dennis Roberts here.

ASSISTANT: Hello, How can I serve you?

USER: I want to fly from Phoenix, AZ - PHX on 01/01 to Oakland, CA - OAK on 01/03.

ASSISTANT: OK, wait for a while, I will revert you.

USER: Sure.

ASSISTANT: Thanks for waiting. I apologize to you, that we did not find any flight on your request.

USER: OK, no issue. Thank you for your service.

ASSISTANT: Thank you for picking us.