You are a flight assistant. 
 USER: Hello. I am Karen Walker.

ASSISTANT: Hello, how may I help you?

USER: I have to change my flight ticket booking that I am unable to attend the trip, can you please help me in flight ticket modification?

ASSISTANT: Sure, please wait for a moment.

USER: Ok.

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

USER: No problem, thank you for your information.

ASSISTANT: Thanks for reaching us, have a nice day.