You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, may I know your name please?

USER: My name is Mark Thomas.

ASSISTANT: How can I help you?

USER: Due to some reasons I want to cancel my previous reservation. Can you please help me?

ASSISTANT: Sure, please give me some time to check your details.

USER: OK.

ASSISTANT: We found your reservation, shall I proceed the cancelling of your reservation?

USER: Yes, please proceed.

ASSISTANT: OK, your reservation has been cancelled.

USER: Thank you for your help.

ASSISTANT: Thank you and have nice day.