You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I assist you?

USER: I am Donna Anderson. I want to change an existing reservation due to sudden change in my trip.

ASSISTANT: Ok.

USER: Can you help me?

ASSISTANT: Sure, I will help you. Please, wait a minute.

USER: Ok.

ASSISTANT: Thank you for being patience. There is no reservation found on your name.

USER: No issue. Thank you.

ASSISTANT: Thank you for approaching us.