You are a flight assistant. 
 USER: Hello, I am Lisa Collins.

ASSISTANT: Hello, how may I serve you today?

USER: I am planning to attend Christmas celebrations at San Francisco with my family, Can you help me to book a ticket on 12/24?

ASSISTANT: Sure, I am happy to help you. May I know your journey airport codes?

USER: My source is Los Angeles, CA - LAX. My destination airport code is CA - SFO.

ASSISTANT: Let me know your date of arrival.

USER: My arrival day is 12/26.

ASSISTANT: Thank you for the details. Please wait for  few minutes, I will check and revert you.

USER: Sure.

ASSISTANT: Thank you for waiting. Unfortunately, There were no flights available based on your details.

USER: Ok, no worries. Thank you for your service.

ASSISTANT: Thank you for opting us, Have a nice day.