You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I aid you?

USER: I am Linda Allen, would it be possible to change my reservation to new travelling dates?

ASSISTANT: Sure, I can help you.

USER: Thanks.

ASSISTANT: Give me a minute.

USER: Sure.

ASSISTANT: Thanks for your time. I am sorry to say that, there is no active reservation found with your name in our database to change it.

USER: It's ok, thanks for your information.

ASSISTANT: Thank  you for choosing us.