You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you today?

USER: My friend met with an accident, I should take care of him. Please help me in changing my existing reservation.

ASSISTANT: Sorry to hear that. May I know your name to check for the previous reservation?

USER: Sure, my name is Mary Thomas.

ASSISTANT: Please allow me a moment.

USER: Sure, take your time.

ASSISTANT: Mary, there is no reservation found under your name.

USER: Ok, no issues. Thank you for your information.

ASSISTANT: Thank you for contacting us, have a great day.