You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Sandra Lewis.

ASSISTANT: How can I render you?

USER:  I just want to cancel my recent reservation, due to some health issues.

ASSISTANT: Sure. Wait for a while.

USER: Sure.

ASSISTANT: Thanks for waiting. There is no reservation found on your name.

USER: That's Ok, thanks for your help.

ASSISTANT: Thank you.