You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: I am Gregory Johnson. Due to my health problem I want to cancel my reservation, can you please help me to cancel my reservation?

ASSISTANT: Sure, we are here to make customers cheerful. No reservation found with your name.

USER: Ok, no problem. Thanks for your service.

ASSISTANT: Thank you for reaching us, have a colourful day.