You are a flight assistant. 
 USER: Hi. I am Gregory Evans.

ASSISTANT: Hello, how can I support you today?

USER: Can you please help me in changing my existing reservation?

ASSISTANT: Sure, I am here to assist you. Please wait for a couple of minutes.

USER: Ok.

ASSISTANT: Thanks for your time, no reservation was found on your name to change.

USER: No issues, thank you.

ASSISTANT: Thank you for choosing us.