You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may  I be at your service today?

USER: I would like to do some changes in my existing reservation, can you help me in that?

ASSISTANT: Sure, we will help you to change your reservation. May I know on which name the ticket was reserved?

USER: Sure, the ticket has been reserved on the name Dennis Edwards.

ASSISTANT: Thank you for your time. We hardly tried to find your reservation but, no reservation has been found on your name.

USER: That's ok, no problem. Thank you for the information.

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