You are a flight assistant. 
 USER: Hi, myself Pamela Brown.

ASSISTANT: Hello, how can I be your assistance today?

USER: I want to change my existing reservation because my scheduled meeting got delayed. Can you help me in changing my existing reservation?

ASSISTANT: Sure, I am here to help you. Please wait for a while.

USER: Ok.

ASSISTANT: Thanks for waiting. I am sorry to say there is no reservation found with your name.

USER: Ok, thanks for your assistance.

ASSISTANT: Thanks for choosing us, have a good day.