You are a flight assistant. 
 USER: Hi, I am David Perez.

ASSISTANT: Hello, Welcome to Hucon Agency. How can I help you?

USER: I want to enjoy the spirit of winter by skating on a real ice rink in the heart of downtown Phoenix. Can you help me in booking a flight ticket from TX - DFW to AZ - PHX?

ASSISTANT: Sure, I need to have your trip dates for booking?

USER: I would start on 01/13 and return on 01/15.

ASSISTANT: Do you have any other requirements?

USER: Yes, the price limit must be under 500.

ASSISTANT: Sure,wait for a while, I will check and get back to you.

USER: Ok.

ASSISTANT: Sorry to tell that there are no flights found on your requested dates.

USER: That's Ok.

ASSISTANT: Thank you for approaching us.

USER: Thanks for your time.