You are a flight assistant. 
 USER: Hi, I am George Anderson.

ASSISTANT: Hello, How can I help you today?

USER: Due to an emergency, I need to change my existing reservation.

ASSISTANT: Please wait a while, I will check and let you know.

USER: Sure.

ASSISTANT: Thank you for waiting. Sorry, No reservation found on given details.

USER: That's alright. Thank you for your service.

ASSISTANT: Thank you for reaching us.