You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Paul Thomas.

ASSISTANT: How may I assist you?

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

ASSISTANT: Sure, please wait.

USER: Ok.

ASSISTANT: Paul Thomas, there is no reservation on your name.

USER: No issue.

ASSISTANT: Thank you.

USER: Thank you for the information.