You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

USER: I am Catherine Perez. I want to change my existing reservation as my exams got postponed. Can you help me in changing reservation?

ASSISTANT: Sure, please wait a minute.

USER: Sure.

ASSISTANT: Thanks for waiting.

USER: Ok.

ASSISTANT: There is no reservation found with your name.

USER: Ok, Not an issue. Thank you.

ASSISTANT: Thanks for availing us.