You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I be at your service today? May I know your good name please?

USER: I'm Jeffrey Turner. I heard very great about your agency, will you please help me in changing my existing reservation?

ASSISTANT: Sure, we are gleeful to help you.

USER: Yes, please check it out.

ASSISTANT: Please wait for a while, I will check the reservation list and revert to you.

USER: Sure.

ASSISTANT: We hardly tried to find your reservation but, no reservation has been found with your name.

USER: That's ok, no issues. Thank you for your service anyways.

ASSISTANT: Thank you for reaching us. Have a good day.