You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Dorothy Smith.

ASSISTANT: How can I help you?

USER: Would it be possible to change my recent reservation to new travel dates?

ASSISTANT: Sure, I am ready to help you.

USER: Thanks.

ASSISTANT: Sorry, there are no reservation found on your name.

USER: It's ok, thanks for checking.

ASSISTANT: Thank you for choosing us.