You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may  I support you today?

USER: I am Andrew Lee. I want to change my existing reservation, due to my exams dates has been changed. Can you help me out?

ASSISTANT: Sure, we are glad to serve you.

USER: Thank you.

ASSISTANT: Please hold a moment.

USER: Sure.

ASSISTANT: Thanks for your time, sorry, no reservation found with you name.

USER: Not an issue. Thank you for your information.

ASSISTANT: Thank you for approaching us, have a great day ahead.