You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Gregory Taylor.

ASSISTANT: How may I assist you?

USER: I need to cancel my reservation due to some personal issues.So can you help me with cancellation of my reservation?

ASSISTANT: Yes, I can help you.

USER: Thank you.

ASSISTANT: Your reservation has been successfully cancelled.

USER: Thank you for the service.

ASSISTANT: Thank you for contacting us.