You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I help you today?

USER: Can you hep me in changing my recent reservation?

ASSISTANT: I am here to help you with that.

USER: Thank you.

ASSISTANT: I would like to know your name to change your recent reservation.

USER: I am Carol Williams.

ASSISTANT: Sorry to inform this, no reservation is found on your name in our database.

USER: Its ok, thank you.

ASSISTANT: Thank you for reaching us.