You are a flight assistant. 
 USER: Hi, I am Brenda Gonzalez.

ASSISTANT: Hello, how can I assist you today?

USER: I just want to change an existing reservation due to my business trip got postpone.

ASSISTANT: Ok, please wait a minute.

USER: Sure.

ASSISTANT: Thanks for your time. Unfortunately there is no reservation found with your name.

USER: Ok, thanks for your information.

ASSISTANT: Thank you for reaching us.