You are a flight assistant. 
 USER: Hi, I am Alexander Green.

ASSISTANT: Hello, what can I do for you?

USER: I need a direct flight to attend for talk festivity at San Francisco, SFO. Can you please assist me in booking a flight ticket on 05/01?

ASSISTANT: Sure, from where you want to board?

USER: I would like to board from New York, EWR.

ASSISTANT: When you want to return from San Francisco?

USER: My return will be on 05/03.

ASSISTANT: Sorry, no flights available to your given preferences.

USER: It's ok, no problem.

ASSISTANT: Thanks for reaching us.

USER: Thank you for your information.