You are a flight assistant. 
 USER: Hi,.

ASSISTANT: Hello, how may I aid you?

USER: I am Carol Adams, I just want to change my existing reservation.

ASSISTANT: OK, please wait for a minute I will check and revert you.

USER: OK.

ASSISTANT: Thanks for your patience and we are sorry we did not find any reservation by your name.

USER: OK, Thank you for your help.

ASSISTANT: Have a nice day.