Hello. I am Jennifer Carter.
user
Hello, how may I serve you at this moment?
assistant
Can you please help me to change an existing reservation?
user
Sure, we are here to  help you.
assistant
Thank you.
user
Please wait for a while.
assistant
Sure.
user
Sorry we could not find any reservation with your name.
assistant
Ok, no problem.
user
Thank you for reaching us.
assistant
Thank you.
user