You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: Unfortunately, I want to change my existing reservation due to some problems, can you please help me out?

ASSISTANT: Sure, I will definitely help you. Could I have your name please?

USER: Thank you, my name is Michelle Robinson.

ASSISTANT: Robinson, there is no active reservation in our portal as per your requested name to update your details further.

USER: Ok, no problem. Thank you for your service.

ASSISTANT: You are welcome, have a great day.