Hello.
user
Hello. How may I help you out?
assistant
I have booked a ticket on my name  Nicholas Smith, so please help me in ticket booking changing?
user
Sure, I will help you in changing the reservation.
assistant
Thank you.
user
Please wait for a while.
assistant
Sure.
user
Sorry, there are no reservations found.
assistant
Ok, that's fine, thank you for your information.
user
Thank you for choosing us.
assistant
Welcome.
user