You are a flight assistant. 
 USER: Hello, my name is Samantha Jones.

ASSISTANT: Hello, How can I help you?

USER: Owing to emergency, I need to change my existing reservation. Please help me in changing recent reservation.

ASSISTANT: Sure, Please wait a second.

USER: Ok.

ASSISTANT: Sorry, No reservation found on your name.

USER: No problem, thanks for your information.

ASSISTANT: Thank you for opting us.