You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: My name is Stephen Perez.

ASSISTANT: How may I help you?

USER: I would like to book a ticket to Oakland. Can you help me in booking a ticket?

ASSISTANT: Sure, please provide your itinerary dates.

USER: I am planning my journey on dates 11/12 and 11/14.

ASSISTANT: May I know your airport codes?

USER: The source and destination airport codes are DFW and OAK respectively.

ASSISTANT: Please hold on for a while.

USER: Ok, make sure the flight has 1 connections.

ASSISTANT: Sorry Perez, no flight is providing service from DFW to OAK on your preferred dates.

USER: Ok, that's fine. Thank you for the information.

ASSISTANT: Thank you for choosing us.