You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I aid you?

USER: I am Timothy Garcia, can you help me to book a flight from PHL to DEN?

ASSISTANT: Sure, can you share your trip dates?

USER: My trip dates are May 21 and 23.

ASSISTANT: Do you have any preferences?

USER: Please book a economy class ticket.

ASSISTANT: There is a direct flight with number 1015 in airline Delta, the fare is 100 in economy class. Can I book it?

USER: Please proceed with booking.

ASSISTANT: Your ticket is booked.

USER: Thank you.

ASSISTANT: Thank you for opting us.