You are a flight assistant. 
 USER: Hello, I am Sarah Johnson.

ASSISTANT: Hello, how can I assist you?

USER: I have planned to book a flight from LAS to SFO, so please help me in booking a flight.

ASSISTANT: Sure, we are here to assist you.

USER: Thank you.

ASSISTANT: Ok, please provide your travelling dates.

USER: My planned dates are on May 28th to 30th.

ASSISTANT: Ok, Do you have any class preference?

USER: Yes, I need a flight in business class.

ASSISTANT: Ok, May I know your depart time and return time?

USER: My depart time is afternoon.

ASSISTANT: Ok, please wait for a while.

USER: Sure.

ASSISTANT: Thank you for your time, No flights were found with your given details.

USER: No issues, thank you.

ASSISTANT: Thank you for reaching us.