You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you today?

USER: I need you to book a flight ticket from SFO to EWR. Please help me.

ASSISTANT: Sure, may I know your connection limit?

USER: I would prefer to reach my destination in a direct flight.

ASSISTANT: Can you please share your planned travel dates?

USER: April 26 and 28 are my planned travelling dates.

ASSISTANT: Do you have any other requirements?

USER: Nothing much to state.

ASSISTANT: May I know your name please?

USER: My name is Mark Williams.

ASSISTANT: Sorry, there are no flights found with your given details.

USER: That's ok. Thank you.

ASSISTANT: Thank you for opting us.