You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you today?

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

ASSISTANT: Sure, may I know your good name please?

USER: I am Richard Campbell.

ASSISTANT: Sorry, there was no reservation found with your given name.

USER: Ok, no problem. Thank you.

ASSISTANT: Thank you for opting us.