You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, How can I serve you?

USER: I am Laura Gonzalez. I want to change my existing reservation, because I need to take up a sudden investigation. Can you help me in changing reservation?

ASSISTANT: Please wait a minute.

USER: Sure.

ASSISTANT: Sorry, No reservation found on your name. Thank you for reaching us.

USER: Ok, No problem. Thank you.