You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, what can I do for you today?

USER: Can you please help me to change my reservation?

ASSISTANT: Sure, may I know your name please?

USER: My name is Robert Anderson.

ASSISTANT:  Sorry, no reservation found on your given name in our database to change it.

USER: Ok, not a problem. Thank you.

ASSISTANT: Thank you for contacting us.