You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

USER: I am Jacob Thompson.

ASSISTANT: Good evening Jacob.

USER: I am planning to change an existing reservation, due to health issue. Can you please change my reservation?

ASSISTANT: Sure, please wait for a minute. I will search for the status of your reservation.

USER: Sure, take you own time.

ASSISTANT: Jacob, there is no reservation found with your details.

USER: That's fine. Thank you for your service.

ASSISTANT: Thank you for reaching us.