You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I give assistance to you?

USER: Can you help me in changing my recent reservation?

ASSISTANT: Sure, I am glad to help you to change it. Can I have your good name please?

USER: Thank you for accepting my request. I am Melissa Lopez.

ASSISTANT: Ok, please wait for a moment.

USER: Sure.

ASSISTANT: Sorry to say that, there was no reservation found on your name to change it.

USER: Its ok, thank you.

ASSISTANT: Thank you for opting our service.