You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: Andrew Carter here.

ASSISTANT: How may I assist you today?

USER: Due to severe health issue, I am not able to catch the flight. Please cancel my recent reservation.

ASSISTANT: Oh! sure. Carter, I cancelled your reservation.

USER: Thank you for the help.

ASSISTANT: Thank you for contacting us. Take care of your health.

USER: Sure.