You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am William Roberts.

ASSISTANT: OK Roberts, how may I guide you?

USER: Actually I want to cancel my recent reservation, because of due to some health problem.Can you help me out?

ASSISTANT: OK Roberts, will you please wait a moment to check it? Thank you for waiting, sorry Roberts, there is no reservation found as per your request.

USER: Thank you for your help.

ASSISTANT: Your welcome, thank you for reaching us.