You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I oblige you today?

USER: I would like to book a flight ticket from ATL to LGA, can you help me with that?

ASSISTANT: Sure, may I know your good name?

USER: I am Paul Garcia.

ASSISTANT: Do you have any class preference?

USER: Nothing.

ASSISTANT: Could you please help me with you journey dates?

USER: My travel dates are 09/19 and 09/21.

ASSISTANT: Is there any other preferences?

USER: I need direct flight.

ASSISTANT: Ok, please wait for a while.

USER: Sure.

ASSISTANT: Sorry, there are no flights found from your source on given dates.

USER: That's ok. Thank you for your service.

ASSISTANT: Thank you for opting us.