You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Kevin Smith.

ASSISTANT: How may I guide you today?

USER: Due to sudden work, I need to change my reservation. Can you please help me with it?

ASSISTANT: Sure, I will help you with that. Please wait a moment to check your previous reservation.

USER: Ok.

ASSISTANT: Sorry to inform you that, there is no reservation found on your name in our records.

USER: Ok, not an issue. Thank you for your information.

ASSISTANT: Thank you for reaching us, have a great day.