You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hi,. How may I aid you?

USER: I am Brenda Gonzalez want to change my existing reservation due to my meeting has been postponed. Can you please assist in that?

ASSISTANT: Sure. Give me a minute.

USER: Sure.

ASSISTANT: Sorry Gonzalez,we did not find any reservation on your name. Thank you for choosing our service.

USER: No problem, thank you.

ASSISTANT: Have a nice day.