You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Donald Thomas.

ASSISTANT: How can I assist you?

USER: I am planning to book a ticket from MCO to DFW. Can you please help me out?

ASSISTANT: Sure, may I know your planned departure and return travel dates please?

USER: I am planning to travel on Dec 13 and return back on Dec 15.

ASSISTANT: Can I know in which class do you prefer to travel?

USER: I am ok with any class.

ASSISTANT: Do you have any specifications regarding departure and arrival time?

USER: My depart time should be evening.

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

USER: I am looking for a connecting flight.

ASSISTANT: Ok, please wait for a while.

USER: Sure.

ASSISTANT: Sorry, there are no flights available on those dates with your given details.

USER: That's fine, thank you for your service.

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