You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I help you?

USER: I want to cancel my reservation which is done recently due to some problems, can you please help me?

ASSISTANT: Sure, please wait a minute.

USER: Ok, I will wait.

ASSISTANT: Sure. May I know your name?

USER: Sure, my name is Mark Clark.

ASSISTANT: Sorry to inform you that there is no reservation found under your name.

USER: Ok, that's fine. Anyways, thank you for your service.

ASSISTANT: Most welcome.