You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: I am Christopher Walker. Can you please book a ticket from PHL to DEN?

ASSISTANT: Sure. May I know the dates?

USER: My preferable dates are 11/19 and 11/21.

ASSISTANT: There is a flight with connection 0 and airlin e is Delta. Can I book it?

USER: Ok, please book it.

ASSISTANT: Your ticket is booked with number 1011. Happy journey.

USER: Thank you for the help.

ASSISTANT: Welcome.