You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I assist you?

USER: I am Jennifer Evans. I want to change my existing reservation due to postpone of my board meeting, so can you please help me with this?

ASSISTANT: Sure, please wait for a while.

USER: Sure, I will wait.

ASSISTANT: We don't have any reservation on your name to change.

USER: Not a problem, thanks for checking.

ASSISTANT: Thank you.