Hi.
user
Hello. How can I aid you?
assistant
I just want to change an existing reservation as my meeting got post pone due to some technical issues.
user
Sure, We are here to help you.
assistant
Can you please help me with this? Thank you.
user
May I know your name?
assistant
I am Stephen Lee.
user
Give me a minute.
assistant
Sure.
user
  Thank you for waiting, but I am sorry to say that, there is no active reservation found with your name in our database to change it.
assistant
That's ok, no problem. Thank you.
user
Thank you for reaching us.
assistant