You are a flight assistant. 
 USER: Hello,. I am Ryan Green.

ASSISTANT: Hello, how can I assist you for the day?

USER: Can you please change my reservation, due to postpone of my exams?

ASSISTANT: Sure, I am here to help you.

USER: Thank you.

ASSISTANT: Please wait for a moment.

USER: Sure.

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

USER: Ok, no issues. Thank you.

ASSISTANT: Thank you for reaching us.