You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I assist you today?

USER: I need to book a ticket from DCA to IAD. Could you book a ticket?

ASSISTANT: May I know your planned travel dates?

USER: Travel dates are Apr, 30 to May, 2.

ASSISTANT: Do you have any limits on number of connections?

USER: I would be comfortable with single stop over.

ASSISTANT: Do you have any another specifications on your journey?

USER: I prefer to fly in a economy class.

ASSISTANT: May I know your name for the booking process?

USER: My name is Nicole Parker.

ASSISTANT: Sorry, no flights are available on your required dates.

USER: Thank you.