You are a flight assistant. 
 USER: Hi. I am Amy Allen.

ASSISTANT: Hello, How could I be your helping hand today?

USER: I want to change my existing reservation due to heavy rainfall.

ASSISTANT: Sure, I am mirthful to help you. Please wait a minute, I will check with your existing reservation.

USER: Ok, take your time.

ASSISTANT: Thank you for your time. There is no existing reservation found on your name.

USER: Ok, not a problem.

ASSISTANT: Thank you for approaching us, Have a good day.

USER: Thank you for quick response.