You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I aid you for the day?

USER: I want to change my existing reservation due to some technical issues. Can you help me with that?

ASSISTANT: Sure, we are here to help you.

USER: Thank you.

ASSISTANT: May I know your name to check in the reservation list?

USER: Sure, I am Donald Harris.

ASSISTANT: Please stay online.

USER: Sure.

ASSISTANT: Thank you for your time. We are regret to say that there is no active reservation found in your given name.

USER: Ok, not a problem. Thank you for your kind information.

ASSISTANT: Thank you for opting us. Have a nice day.