You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: I want to change my existing reservation due to prepone of my meeting dates. Can you please help me in that?

ASSISTANT: Sure, may I know your name please?

USER: George Scott here.

ASSISTANT: I am sorry no reservation found on your name.

USER: Ok, not an issue.

ASSISTANT: Thank you for choosing us.

USER: Thank you for checking.