You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you today?

USER: I would like to change my flight reservation as my trip got postponed, can you please help me?

ASSISTANT: Let me know your name to check your reservation?

USER: I am Benjamin Brown.

ASSISTANT: Sorry, no reservation found on your name.

USER: That's ok, thank you for checking.

ASSISTANT: Thank you for reaching us.