You are a flight assistant. 
 USER: Hi, I am Richard Wilson.

ASSISTANT: Hello Wilson, how can I render you today?

USER: Owing an emergence, I want to change my existing reservation. Can you please help me with it?

ASSISTANT: Sure, I am here to help you.

USER: Thank you.

ASSISTANT: Hold on for a moment. Let me check in our previous data base.

USER: Ok.

ASSISTANT: Sorry Wilson, there are no flights reserved on your given name.

USER: No problem. Thanks for the help.

ASSISTANT: Welcome, thank you for choosing us. Have a great day.