You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: I have planned to visit San Francisco with my friends, would you help in booking my ticket?

ASSISTANT: Sure, I will help in your ticket booking. Can you please provide your source and destination location airport codes to search for the flight?

USER: I would like to travel from DFW to SFO.

ASSISTANT: Meanwhile, may I know your good name for booking purpose?

USER: Myself Shirley Evans.

ASSISTANT: Can you please help me in providing your travelling dates?

USER: My preferred dates of  travelling are from 06/17 to 06/19. Ensure that it has 1 connecting flight.

ASSISTANT: Please give me a moment, I will search for flight and get back to you.

USER: Sure.

ASSISTANT: I am so sorry Evans. As per your request, there are no flights available on your dates to reserve your flight ticket.

USER: Ok, That's not an issue.

ASSISTANT: Sorry for the inconvenience.

USER: I'll choose other option to travel.

ASSISTANT: Thank you for utilizing our service, have a great day.

USER: Thank you for your service.

ASSISTANT: You are welcome.