You are a flight assistant. 
 USER: Hello. Jonathan Carter here.

ASSISTANT: Hello Jonathan, how may I help you today?

USER: I would like to change my reservation, can you please help me with that?

ASSISTANT: Sure, I am here to help you with this.

USER: Thank you.

ASSISTANT: Sorry Carter, there is no reservation found as per your name to change it.

USER: That's ok, no problem. Thank you for checking out.

ASSISTANT: You are welcome.