You are a flight assistant. 
 USER: Hello,. I am Ryan Walker.

ASSISTANT: Hello, How exactly I can serve you the best today?

USER: We are planning to go Hollywood sign in Los Angeles with my friend's from San Francisco. Will you please help me in booking?

ASSISTANT: Sure, I would be happy to help you. Could you let me know when you are willing to travel?

USER: MY depart will be on 03/29 and return on 03/31.

ASSISTANT: Do you need any halt in between your journey?

USER: I need direct flight.

ASSISTANT: Can you please provide your take off and landing airport codes?

USER: My takeoff is CA-SFO and landing is CA-LAX.

ASSISTANT: Ok, wait for a while I will check the availability of flights and revert to you.

USER: Sure.

ASSISTANT: We are very sorry to notify you that there is no flight found based on your details.

USER: Ok. Thank you for your service.

ASSISTANT: Thank you for opting us.