You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Melissa Edwards.

ASSISTANT: How can I assist you?

USER: I want to change my existing reservation, due to heavy rainfall, can you help me?

ASSISTANT: Sure, I am here to help you. Please wait a minute.

USER: Sure.

ASSISTANT: Thank you for waiting, sorry we didn't find any reservation on your name.

USER: That's ok, thank you for your information.

ASSISTANT: Thank you for reaching us, have a good day.