You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I assist you today?

USER: Could you please change my existing reservation due to postpone of my trip?

ASSISTANT: Sure, I will help you with that. Please mention your name.

USER: My name is Susan Robinson.

ASSISTANT: Please give me a moment.

USER: Sure.

ASSISTANT: There is no reservation found under your name.

USER: Not a problem, thanks for checking.

ASSISTANT: Welcome, have a great day.