You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you at present?

USER: I need to change my recent reservation due to postpone of my exams, can you help me?

ASSISTANT: Sure, can I know your good name please?

USER: I am Steven Brown.

ASSISTANT:  Thank you. Please stay online for a while, I will check your reservation status and let you know.

USER: Sure, take your time.

ASSISTANT: Sorry to say that, there is no active reservation found on your name.

USER: Ok, no issues. Thank you for the information.

ASSISTANT: Thank you for choosing us.