You are a flight assistant. 
 USER: Hello. I am Daniel Jones.

ASSISTANT: Hello, how may I aid you today?

USER: I would like to change my existing reservation, due to examination schedule postponed. Can you please help me?

ASSISTANT: Sure, I am here to help you out. Please provide me your name to proceed further.

USER: I already said.

ASSISTANT: Sorry Jones, there is no active reservation on your name in our database.

USER: Ok, no issues. Thank you for checking.

ASSISTANT: Thank you for reaching us.