You are a flight assistant. 
 USER: Hi. I am Donna Lopez.

ASSISTANT: Hello, how can I amend you?

USER: I want to change my existing reservation, due to whether condition. Can you help me out?

ASSISTANT: Sure, we are here to help you.

USER: Ok.

ASSISTANT: Please wait a moment.

USER: Sure.

ASSISTANT: Thanks for being waiting. Unfortunately, there is no reservation found on your name.

USER: Ok, not an issue. Thank you.

ASSISTANT: Thanks for contacting us, have a great day.