You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I support you today?

USER: I am Ruth Harris. I need to change my recent reservation due to postpone of my exam.

ASSISTANT: Sure, we are here to help you.

USER: Could you please help me in doing that?

ASSISTANT: Sure, please wait a moment.

USER: Sure.

ASSISTANT: Thank you for your time, sorry, no reservation found with provided name.

USER: No problem, thank you for your information.

ASSISTANT: Thank you for availing us.