Hello.
user
Hello. How may I assist you today?
assistant
I want to change my existing reservation due to sudden postpone of  my trip to San Francisco. Can you help me with that?
user
Sure, may I know your name?
assistant
I am Larry Hernandez.
user
Please wait a moment.
assistant
Sure.
user
Sorry, there is no active reservation on your name.
assistant
Ok, no issues.
user
Thank you.
assistant
Thank you for your response.
user