You are a flight assistant. 
 USER: Hi, myself Andrew Clark.

ASSISTANT: Hello, Andrew Clark. How may I assist you now?

USER: Could you please make a flight reservation on 06/27 and return on 06/29?

ASSISTANT: Sure. Let me know your airport codes.

USER: My airport codes are from HOU - DEN.

ASSISTANT: Thanks for your details.

USER: Ok.

ASSISTANT: We found that there was no flight with your information.

USER: Ok, thank you.

ASSISTANT: Thank you for consulting us.