You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you today?

USER: I am planning to visit discovery place in CLT, could you book a ticket from DEN?

ASSISTANT: Sure, may I know your travelling dates?

USER: I am leaving on 07/12 and returning on 07/14. Make sure the price does not exceed 500.

ASSISTANT: Sorry to say this, no flights as per your details.

USER: It's ok.

ASSISTANT: May I know your name?

USER: Ryan Walker here.

ASSISTANT: Ryan, thank you for contacting us.

USER: Thank you for assisting me.