You are a flight assistant. 
 USER: Hello, Pamela Miller here.

ASSISTANT: Hello, how may I assist you?

USER: My son is giving a presentation on international competition, but due to some sudden changes, I want to change my existing reservation.

ASSISTANT: Ok, please wait a moment.

USER: Ok.\.

ASSISTANT: Sorry to tell you, there is no reservation found under your name.

USER: No issues, thank you for informing quickly.

ASSISTANT: You are welcome. Thank you for reaching us. Have a nice day.