You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I aid you?

USER: Could you please help me to book a direct flight from Atlanta to attend a business meeting in San Francisco?

ASSISTANT: Sure, I am ready to help you. Could you please provide me your journey dates?

USER: Mar 29th and Mar 31 are my planned travelling dates.

ASSISTANT: May I know your airport codes please?

USER: My source point is ATL and my  destination point is SFO.

ASSISTANT: Do you have any specifications?

USER: I would like to fly with the normal cost airline.

ASSISTANT: May I know your name?

USER: I am Patricia Walker.

ASSISTANT: Do you have any preferences?

USER: No.

ASSISTANT: Sorry, there are no flights found on your trip dates.

USER: No issues, I'll choose any alternative. Thank you.

ASSISTANT: Thank you for choosing us.