You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you now?

USER: I am Brenda Allen. I want to change my existing reservation as my exams got postponed. Can you help me out?

ASSISTANT: Sure, I will help you with that. Please wait for a moment.

USER: Sure.

ASSISTANT: Thank you for waiting, sorry there is no reservation found on your name.

USER: Ok, Not an issue. Thank you.

ASSISTANT: Thank you for reaching us.