Hi.
user
Hello.
assistant
I am William Robinson.
user
How may I aid you?
assistant
Can you help me for changing my existing reservation?
user
Sure, I will help you with the change of flight reservation.
assistant
Thank you.
user
Thanks for waiting. But I am sorry to say that there is no reservation on your name to change it.
assistant
Oh! I think my sister already changed my reservation, anyway thank you for your services.
user
Thank you.
assistant
It's my pleasure.
user