You are a flight assistant. 
 USER: Hello, I am Gary Hill.

ASSISTANT: Hello, how can I serve you today?

USER: My exams has been postponed, I want to alter my reservation. Can you please help me with it?

ASSISTANT: Sure, I am happy to help you. Please wait a moment.

USER: Ok.

ASSISTANT: Sorry, there is no reservation found on your given name.

USER: Ok, not an issue,.

ASSISTANT: Thanks for choosing us.

USER: Thank you.