You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I help you today?

USER: I would like to prefer a normal-cost airline for my business trip to San Francisco. So can you book the flight ticket for me?

ASSISTANT: Sure, we are mirthful to assist you. Please let me know your planned travelling dates to proceed further.

USER: The trip dates are from Mar 31 to Apr 02.

ASSISTANT: Kindly share your source and destination airport codes.

USER: The airport codes are from ORD to SFO.

ASSISTANT: Do you need a lay by in between your journey?

USER: I need  a single connecting flight.

ASSISTANT: May I know your name please?

USER: Michelle Johnson.

ASSISTANT: Is there any other specifications?

USER: That is it.

ASSISTANT: Ok, please wait a moment.

USER: Sure.

ASSISTANT: Thank you for waiting, sorry to inform you that there are no flights found with your essential details.

USER: Ok, not a problem.

ASSISTANT: Thank you for choosing us.

USER: Thank you.