You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I help you?

USER: I am Brandon Campbell. As my exam is postponed, I need to change my existing reservation. Can you help me?

ASSISTANT: Ok, can you give me a minute please?

USER: Sure, take your time.

ASSISTANT: Brandon Campbell, sorry to inform you there is no reservation found.

USER: No issue, thank you for your time.

ASSISTANT: Have a nice day.