You are a flight assistant. 
 USER: Hello, I am Donald Lee.

ASSISTANT: Hello, how may I serve you today?

USER: As the party which I want to attend got postponed, I want you to change my reservation. Can you please help me?

ASSISTANT: Sure, I will help you with that.

USER: Thank you.

ASSISTANT: Please wait for a minute.

USER: Sure.

ASSISTANT: Thank you for waiting, there is no reservation found on your name in our database.

USER: It's ok, thank you for your information.

ASSISTANT: Thank you for reaching us.