You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you?

USER: I am Patrick Collins. I am planning to attend a Tennis competition in SFO from BOS. Can you find a flight ticket for me?

ASSISTANT: Sure, I am here to assist you. Can you please let me know your travel dates?

USER: Ok, my planned trip dates are on June 28 and return on June 30.

ASSISTANT: Ok, may I know your preferences?

USER: Yes, I want to return on Evening time.

ASSISTANT: Sorry, there is no flight available as per your requirements.

USER: Ok, not an problem. Thank you for your information.

ASSISTANT: You are welcome and thank you for choosing us.