You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Catherine Lopez.

ASSISTANT: How can I serve you?

USER: I need to change my recent reservation due to postpone of my exams. Could you please help me in doing that?

ASSISTANT: Ok. Please wait.

USER: Sure.

ASSISTANT: Thanks for waiting. There is no reservation found on your name.

USER: No problem, thank you for your information.

ASSISTANT: Thank you.