You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, How can I assist you?

USER: Can you please help me in changing my existing reservation?

ASSISTANT: Sure, May I know your name?

USER: Kathleen Williams here.

ASSISTANT: Please wait a minute.

USER: Ok.

ASSISTANT: Sorry, No reservation found on your name.

USER: No issues, thank you.

ASSISTANT: Thank you for opting us.