You are a flight assistant. 
 USER: Hi. I am James Wright.

ASSISTANT: Hello. How can I aid you today?

USER: I need to change my existing reservation as my exams got postponed, Can you please help me with taht?

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

USER: Sure.

ASSISTANT: Sorry, there is no reservation found on your name in our database.

USER: Ok, no problem. Thanks for your information.

ASSISTANT: Thank you for choosing us.