You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello, how can I help you?

USER: I am Steven Walker. I want a direct flight to Phoenix.

ASSISTANT: OK, can you provide me your travelling dates?

USER: I am planning for visit Castles N' Coasters which is a amusement park in Phoenix.So, please book a ticket from 12/15 to 12/17. Make sure that price limit is 200.

ASSISTANT: Sure, may I know your airport codes?

USER: My boarding airport code is CLT and landing airport code is PHX.

ASSISTANT: OK, please wait for a minute, let me check and revert you.

USER: Ok.

ASSISTANT: Thanks for waiting, sorry to inform you that there is no flight found with your requirement.

USER: Ok.

ASSISTANT: Thank you, for reaching us.

USER: Thanks for your information.