You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: I am Ruth Green.

ASSISTANT: Ok.

USER: My business meeting is postponed, so I need your help to change my existing reservation, can you help me?

ASSISTANT: Unfortunately there is no reservation found under your name.

USER: Thank you for your help.

ASSISTANT: Thank you for reaching us.Have a nice day.