You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you?

USER: My name is Mark Allen. I am looking to book a flight ticket to meet my brother in Atlanta. Can you help me for booking a flight ticket from EWR to ATL?

ASSISTANT: Sure, on what dates are you planning to travel?

USER: My travelling dates are Nov 19 and Nov 21.

ASSISTANT: Is there any class preference?

USER: Any class is fine for me.

ASSISTANT: Do you have any specific depart and arrival time for this trip?

USER: My departure time is morning.

ASSISTANT: Are you okay with a single flag stop within your journey?

USER: Ok.

ASSISTANT: Thank you for providing all necessary details. Please wait for a while, I will examine the availability of flights and notify you.

USER: Ok.

ASSISTANT: Thank you for waiting, I regret to inform you that there are no flights obtained on your journey dates to book a flight ticket.

USER: That's ok, thank you for checking.

ASSISTANT: Thank you for opting us.