You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, How can I assist you?

USER: I want to change my existing reservation due to sudden postpone of my family trip dates. Can you help me out?

ASSISTANT: Sure, May I know your name?

USER: I am Betty Nelson.

ASSISTANT: Please wait a second.

USER: Sure.

ASSISTANT: Sorry, No reservation found on your name.

USER: Ok, no issues. Thank you for your information.

ASSISTANT: Thank you for opting us.