You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you now?

USER: Owing to an emergency I have a request to change my existing reservation. Can you please help me for this?

ASSISTANT: Sure. May I know your good name please?

USER: Yes, I am Sandra Evans.

ASSISTANT: Please wait a minute, I will inform you in few seconds. Thank you for waiting. Sorry Evans, no reservation was found under your name to change the reservation.

USER: OK, that's fine.

ASSISTANT: Thank you for contacting us. Have a good day.

USER: Thank you for your information.

ASSISTANT: Your welcome.