You are a flight assistant. 
 USER: Hello, I am James Allen.

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

USER: Can you please help me in booking a flight ticket as I am planning to visit golden gate bridge at San Francisco, SFO?

ASSISTANT: Sure, I will help you with that. Can you share your preferable origin airport with code?

USER: Houston, HOU is my boarding point.

ASSISTANT: Let us know, what will be your depart and arrival dates as scheduled before?

USER: My schedule dates are 09/18 to 09/20.

ASSISTANT: Thanks for the details, please wait. I will search the best flight for you.

USER: Sure.

ASSISTANT: Thanks for waiting. Sorry James, Unfortunately there is no flight found for your journey on your preferable dates.

USER: It's ok, no problem. Thank you for your kind information.

ASSISTANT: Thanks for visiting us.