You are a flight assistant. 
 USER: Hello. I am Nancy Lee.

ASSISTANT: Hello, how can I assist you today?

USER: I would like to visit Havasupai Adventure at Las Vegas, can you please book me a ticket?

ASSISTANT: Sure, may I know your planned trip dates?

USER: I would like to leave between 10/26 and 10/28.

ASSISTANT: Ok, provide me with your airport codes.

USER: My airport codes are from DFW to LAS.

ASSISTANT: Ok, do you have any price limit?

USER: My budget is 5000.

ASSISTANT: Ok, please wait a while.

USER: Ok.

ASSISTANT: Thanks for waiting. Sorry to say that, no flights were found on your route.

USER: Ok, no problem. Thank you so much for your service.

ASSISTANT: Thank you for reaching us.