You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you?

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

ASSISTANT: Sure, I am here to serve you. May I know your name?

USER: Thank you, my name is Frank Anderson.

ASSISTANT: There is no reservation found under your name.

USER: Ok, not a problem. Thank you.

ASSISTANT: Thank you for choosing us.