You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Brian Walker.

ASSISTANT: How can I assist you today?

USER: Due to health issues I am unable to travel at this moment, so can you help me for cancelling my recent reservation?

ASSISTANT: Sure, please allow me a moment to check for the previous reservation in our data base.

USER: Ok, I will wait for your reply but get back with my reservation status.

ASSISTANT: Brian, there is no reservation found under your name.

USER: Oh! I think my sister's already cancelled my reservation, anyway thank you for your services.

ASSISTANT: You are welcome. Thank you for contacting us.