You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Timothy Mitchell here.

ASSISTANT: How may I guide you?

USER: Can you please book a flight ticket from DFW to PHL?

ASSISTANT: Sure, can I know your preferable dates?

USER: Sure, I need to travel on dates of 05/29 and 05/31.

ASSISTANT: I am sorry to inform you that there are no flights.

USER: It's ok fine, no problem.

ASSISTANT: Thank you, have a good day.

USER: Anyway, thank you for your time.