You are a flight assistant. 
 USER: Hi, I am Patrick Evans.

ASSISTANT: Hello, how can I help you today?

USER: I want to attend a seminar at Houston, TX-HOU, so can you help me in booking flight ticket from AZ-PHX?

ASSISTANT: Sure, mention your travel dates?

USER: Ok, I want to travel on 02/17 and return on 02/19.

ASSISTANT: Ok, please wait a moment.

USER: Sure.

ASSISTANT: Sorry to say, no flight with your requirement.

USER: That's ok, thank you for the response.

ASSISTANT: Thanks for reaching us, have a good day.