You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I assist you?

USER: Due to some issues, I am willing to change my existing reservation. Can you please help me for this?

ASSISTANT: Sure, may I know your name?

USER: I am Jacob Gonzalez.

ASSISTANT: Sorry, there is no reservation found on your name.

USER: That's ok, thank you.

ASSISTANT: Thank you for choosing us.