You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Jack Lee here.

ASSISTANT: How can I assist you?

USER: I have to attend a photo shoot at Las Vegas, can you please help me out in booking the ticket from SFO to LAX?

ASSISTANT: Sure, may I know when are you planning your journey?

USER: Sure, my planned departure and return travel dates are 12/22 and 12/24.

ASSISTANT: Please give me a minute.

USER: Sure, I'll wait for your response.

ASSISTANT: There are no flights available at this moment, Lee.

USER: Oh! That's ok, thank you for giving the information.

ASSISTANT: Thank you for choosing us.