You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, do you need any help from us?

USER: I need to cancel my ticket due to my health issue, can you help me?

ASSISTANT: Sure, could I have your name please?

USER: I am John Lee.

ASSISTANT: Ok, please allow me a moment.

USER: Sure.

ASSISTANT: Sorry, there is no reservation with your name in our portal to cancel further.

USER: That's ok. Thank you for your help.

ASSISTANT: You are welcome, have a great day.