You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, Good Morning. How may I guide you?

USER: I'm Melissa Mitchell. I'd like to re modify my existing reservation due to heavy rain.

ASSISTANT: Sure, please hold on for a minute, let me check.

USER: Sure, take your time.

ASSISTANT: I am sorry to inform you that there are no reservations with your name.

USER: Ok. Thank you for the information.

ASSISTANT: Thank you, have a good day.