You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Carolyn Smith.

ASSISTANT: How can I aid you today?

USER: I would like to change my existing reservation, due to heavy rain fall. Can you please help me?

ASSISTANT: I am very gleeful to help you in changing your reservation.

USER: Thank you.

ASSISTANT: Just give a moment.

USER: Sure, take your own time.

ASSISTANT: Sorry to say this, I had checked in reservation list on your name, no reservation is found.

USER: That's ok, thank you for checking.

ASSISTANT: Thank you for opting us.