You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I aid you today from my end?

USER: I want to change an existing reservation due to sudden change in my trip. Can you help me?

ASSISTANT: Sure, I am here to help you out. Please provide me your name.

USER: Thank you. Ronald Edwards.

ASSISTANT: Sorry, there is no reservation on your name in our database.

USER: Ok, No issue. Thank you.

ASSISTANT: Thank you for reaching us.