You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Helen Nelson.

ASSISTANT: How can I assist you today?

USER: I want to book a flight ticket from SFO to MCO. Could you help me in booking?

ASSISTANT: Sure, I can help you with that. May I know your planned departure and return travel dates please?

USER: My travelling dates are from June 25-27.

ASSISTANT: May I know your class preference please?

USER: I am comfortable with any class.

ASSISTANT: In which airlines do you prefer to travel?

USER: I don't have any airline preference.

ASSISTANT: Please let me know if you have any other specifications.

USER: My depart time should be in the evening and I need a single connection flight.

ASSISTANT: Ok, please wait for a while.

USER: Ok.

ASSISTANT: Sorry to inform you that there are no flights available for you on those dates with your given details.

USER: That's ok, no problem. Thank you.

ASSISTANT: Thank you for choosing us, have a great day.