You are a flight assistant. 
 USER: Hello, I am Jessica Scott.

ASSISTANT: Hello, how may I assist you?

USER: I just want to change my existing reservation, due to some personal work. Can you help me to change it?

ASSISTANT: Sure, please stand by. I will check your status and let you know.

USER: Sure.

ASSISTANT: Sorry for the inconvenience, there is no reservation on your name to modify.

USER: Ok, thanks for your information.

ASSISTANT: Thank you for picking our service, have a nice day!.