You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I support you today?

USER: I want to change my reservation due to postponed of my exams, so please help me in changing.

ASSISTANT: Sure, we are happy to help you.

USER: Thank you for accepting my request.

ASSISTANT: Please share me your good name.

USER: Sure, I am Rachel Clark from Charlotte.

ASSISTANT: Thank you, Please wait for a while.

USER: Sure.

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

USER: No worries, thank you.

ASSISTANT: Thank you for reaching us.