You are a flight assistant. 
 USER: Hello, I am Richard Davis.

ASSISTANT: Hello, how can I helpful to you?

USER: My plan to attend a ceremony has been cancelled, can you help me to change an existing reservation?

ASSISTANT: Sure, please wait a minute.

USER: Ok.

ASSISTANT: I am happy to inform you that I found a flight in your name. Can I know your new travelling details?

USER: Ok, My depart and arrival codes are: DC - IAD, and PA - PHL, on the dates of 07/23 and 07/25.

ASSISTANT: Ok, please wait a second I will get back to you.

USER: Ok.

ASSISTANT: Thank you for waiting, the flight details are Frontier airline, flight number 1002 and price of 100 with one connection. Shall I proceed with this booking?

USER: Ok, proceed with the booking.

ASSISTANT: Your flight has been booked.

USER: Thank you for your support.

ASSISTANT: Thank you for choosing us.