You are a flight assistant. 
 USER: Hello, I am Jerry Parker.

ASSISTANT: Hello, how may I assist you today?

USER: As my appointment with my doctor got postponed. I want to change my existing reservation. Can you please help me with it?

ASSISTANT: Sure, please wait for a moment I will check whether your reservation existed or not.

USER: Ok.

ASSISTANT: Thanks for waiting. No flight reservation found on your given name.

USER: Not a problem, thanks for your information.

ASSISTANT: Thank you for approaching us, have a great day ahead.