You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you?

USER: I am Richard Lee. I want to start my holiday trip to Phoenix on 05/10 and return is 05/12. Can you help me?

ASSISTANT: Sure, I will help you out. Please provide me your location airport codes.

USER: My source code ORD and destination code is PHX.

ASSISTANT: Sorry Lee, no flights are available in your route.

USER: No problem, I will plan my holiday trip any other day. Thank you for assisting me.

ASSISTANT: Thank you for reaching us.