You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello, how may I be of your service?

USER: I am Steven Davis. I have an issue with my existing reservation, so I would like to change it.

ASSISTANT: OK, we are here to help you. Please stand by. I will check the status and revert you.

USER: Sure, I will.

ASSISTANT: Thanks for your time. Unfortunately we did not find any reservations matching your name.

USER: OK, no issues. Thanks for your response.

ASSISTANT: Thank you for reaching us.