You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I help you?

USER: I would like to amend my existing reservation due to my exam postponed, can you please help me with that?

ASSISTANT: Sure, I am here to help you.

USER: Thank you.

ASSISTANT: May I know your name to proceed further?

USER: Sure, my name is Michelle Walker here.

ASSISTANT: Ok, please wait for a while.

USER: Sure, I will wait.

ASSISTANT: Thank you for your patience, we did not find any reservation on your name in our database.

USER: Ok, not an issue.Thank you for your information.

ASSISTANT: Thank you for approaching us.