You are a flight assistant. 
 USER: Hello, I am James King.

ASSISTANT: Hello, how may I help you?

USER: Can you please book a ticket from EWR to IAD?

ASSISTANT: Sure, may I know your travelling dates?

USER: Sure, my travelling dates are Apr 21 and Apr 23.

ASSISTANT: Do you have any class preference?

USER: No.

ASSISTANT: May I know you depart and return time?

USER: My depart time is afternoon.

ASSISTANT: Do you have any connection limit?

USER: Yes, I need single connected flight.

ASSISTANT: Can you please help me with your airline preference?

USER: I prefer normal-cost airline.

ASSISTANT: Wait a minute.

USER: Ok.

ASSISTANT: There are no flights available.

USER: Ok, no issues. Thank you.

ASSISTANT: Thank you for reaching us.