You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I guide you?

USER: Gary Lee here.

ASSISTANT: Yes, I am gleeful to help you.

USER: Due to sudden health issue, I am not able to travel in a flight on those dates, so can you please help me out with cancelling of my reservation?

ASSISTANT: Sad to hear Gray, please give me a moment to check it.

USER: Sure, take your time to check.

ASSISTANT: Lee I am sorry that, no reservation is obtained when I searched in our back end data.

USER: Oh! I think my cousin had cancelled my reservation.

ASSISTANT: Thank you for approaching us.

USER: Anyway, thank you for the information.

ASSISTANT: You are most welcome.