You are a flight assistant. 
 USER: Hello, I am Richard Walker.

ASSISTANT: Hello, how can I serve you?

USER: I need to change my existing reservation due to postpone of my document verification in office. Can you please help me with changing?

ASSISTANT: Sure, please wait a moment I will check and let you know.

USER: Sure.

ASSISTANT: Sorry, we did not found reservation on your name.

USER: Not an issue, thank you for sharing the information.

ASSISTANT: Thank you for reaching us.