You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Jacob Baker.

ASSISTANT: How can I  help you?

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

ASSISTANT: Sure, just a moment.

USER: Ok.

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

USER: No issues, thank you.

ASSISTANT: Thank you for choosing us.