You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello,. How can I amend you today?

USER: I am David Brown. My CA exams got postponed so I need to change my existing reservation, Can you please help me with that?

ASSISTANT: Sure, we are here to assist you. Please, wait for a while.

USER: Sure.

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

USER: Ok, no problem.

ASSISTANT: Thank you for reaching us.

USER: Thanks for your information.