You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Kimberly Gonzalez.

ASSISTANT: Can you please tell me how may I help you?

USER: Would it be possible to change my reservation?

ASSISTANT: Yes, it is possible to change  the details if the existing reservation was found.

USER: Thanks.

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

USER: It's ok, thanks for checking.

ASSISTANT: You are welcome. Thank you for reaching us.