You are a flight assistant. 
 USER: Hi, Alexander Johnson here.

ASSISTANT: Hello, How may I help you today?

USER: I want to cancel my ticket due to my health issue, will you help me over that?

ASSISTANT: please wait for a moment, let me check your details.

USER: Ok.

ASSISTANT: I am sorry there is no reservation with your details.

USER: Thank you for your information.

ASSISTANT: You are welcome.