You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you today?

USER: I need to amend my existing reservation due to postponed business trip, can you please help me?

ASSISTANT: Sure, I am here to help you.

USER: Thank you.

ASSISTANT: Can you please mention your name?

USER: Sure, I am Andrew Edwards here.

ASSISTANT: Sorry, no reservation found with your given name.

USER: Ok, not an issue.

ASSISTANT: Thank you for choosing us.

USER: Thank you for your information.