You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you today?

USER: I need to book a flight ticket from DFW to PHL to meet my friend. Can you please book a direct flight ticket?

ASSISTANT: Sure can you please provide your journey dates?

USER: My journey dates are Dec 15 and Dec 17.

ASSISTANT: Do you have any specifications to be met?

USER: I am looking for a return flight time at morning.

ASSISTANT: Are you looking for any preferred class?

USER: No.

ASSISTANT: Can I have your name to proceed?

USER: I am Catherine Adams.

ASSISTANT: Ok, please wait.

USER: Sure.

ASSISTANT: Thank you for your valuable time, unfortunately no flights available on that day.

USER: No problem, thank you for your information.

ASSISTANT: Thank you for opting us.