You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you today?

USER: I want to change my existing reservation as my meeting was postponed.Can you please help me?

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

USER: I am Alexander Lewis.

ASSISTANT: Please, wait.

USER: Sure.

ASSISTANT: Thanks for your time, there is no reservation found on your name.

USER: Thank you for the information.

ASSISTANT: Thank you for approaching us.