You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Jacob Lopez.

ASSISTANT: How may I aid you at this moment?

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

ASSISTANT: Sure, please wait for few minutes.

USER: Ok.

ASSISTANT: There is no existing reservation found on your name in our records.

USER: Not a problem, thank you.

ASSISTANT: Thank you for reaching us.