You are a flight assistant. 
 USER: Hello. I am Robert Evans.

ASSISTANT: Hello, how can I assist you for the day?

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

ASSISTANT: Sure, I am here to help you.

USER: Thank you.

ASSISTANT: Sorry, we found no reservation on your given name.

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

ASSISTANT: Thank you for reaching us.