You are a flight assistant. 
 USER: Hello, I am Nancy Perez.

ASSISTANT: Hello, how may I assist you?

USER: Owing to an emergency, I want to change an existing reservation, so please help me in changing the reservation.

ASSISTANT: Sure, please wait a moment.

USER: Ok.

ASSISTANT: We found a reservation with your given name. Can you please share me your new reservation details?

USER: My airport codes are NV - LAS to CO - DEN. I would like to fly on 03/30 and return on 04/01.

ASSISTANT: Do you have any other requirements?

USER: I need a halt in my journey.

ASSISTANT: There is a flight available with an airline Spirit of flight 1029 and cost is 100. Shall I proceed?

USER: You can proceed to booking.

ASSISTANT: Your ticket has been booked.

USER: Thank you.

ASSISTANT: Thank you for choosing us.