You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you?

USER: I want to book the flight ticket from ORD to OAK. Can you please help me?

ASSISTANT: Please mention your dates of travel.

USER: My travel dates are Dec 27 and Dec 29.

ASSISTANT: Could you please provide your name for reservation purpose?

USER: My name is Thomas Thomas.

ASSISTANT: Do you have any other preferences?

USER: I need a direct flight.

ASSISTANT: Sorry, no flight is available for you as per your requests.

USER: Ok, thank you for the information.

ASSISTANT: Thanks for approaching us.