Hello.
user
Hello. How may I help you for today?
assistant
I am Sarah White. I am planning to change an existing reservation because of some  urgent work at office.Can you please help me out to change reservation?
user
Yes, I will try for best assistance. Hold on for a second, I will check for your previous reservation.
assistant
That's really great, take your own time.
user
Sorry to inform you that there is no reservation found on on your name in our database. Anything else I can help you with?
assistant
No, I don't have any other plans.
user
Thank you for reaching us.
assistant
Thank you for your service.
user
Feel free to reach us anytime.
assistant
That's fine.
user