You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

USER: I am Helen Robinson, I want to change my reservation as my plan to visit Austin for vacation is postponed. Can you help me with that?

ASSISTANT: Sure, please wait a minute.

USER: Sure.

ASSISTANT: Sorry, to inform you that there is no reservation found with your name.

USER: Thank you for the information.

ASSISTANT: 'Thank you for reaching us.