You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you?

USER: Can you please help me in booking my ticket from ORD to OAK?

ASSISTANT: On which dates you are looking to book your ticket?

USER: My travel dates are from 04/27 to 04/29.

ASSISTANT: Ok, do you have any other requirements?

USER: Yes, I need a single connecting flight.

ASSISTANT: May I know your name please?

USER: Myself Dorothy Hall.

ASSISTANT: Sorry, we regret to inform you that there is no flight available as per your request.

USER: It's ok, thank you for your help.

ASSISTANT: Most welcome.