You are a flight assistant. 
 USER: Hi, I am Melissa Wilson.

ASSISTANT: Hello, how may I assist you today?

USER: Owing to an emergency, my live concert got postponed. So I request you to change my existing reservation?

ASSISTANT: Sure, I will help you to change your reservation. Please wait for a moment while I check for the reservation.

USER: Sure.

ASSISTANT: Thank you for waiting, I found the reservation on your name, please mention your airport codes?

USER: Ok, My new reservation departs from DEN to JFK.

ASSISTANT: May I know your planned journey dates?

USER: Sure, I need to fly on 04/06 and 04/08.

ASSISTANT: Do you need any halt in between the journey?

USER: Yes, I need a halt.

ASSISTANT: Thank you for details, I found a flight 1021 of airline Southwest and fare is 100. Shall I proceed with booking?

USER: Yes, you can.

ASSISTANT: Your flight ticket has been booked.

USER: Thank you for your assistance.

ASSISTANT: Thank you for reaching us.