You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I help you?

USER: Could you please help me to book an economy class ticket from IL to attend an interview in DC?

ASSISTANT: Your travelling dates please?

USER: I intend to depart on Dec 18th and my return date will be on Dec 20th.

ASSISTANT: Do you have any specifications?

USER: I want to fly with the normal cost airline.

ASSISTANT: May I know your airport codes please?

USER: My source and destination airport codes are ORD and IAD.

ASSISTANT: May I know your connection limit please?

USER: I need a connecting flight.

ASSISTANT: May I know your name please?

USER: I am Sandra Davis.

ASSISTANT: I am sorry no flights found on your route.

USER: Ok, not an issue. Thank you for your information.

ASSISTANT: Thank you for choosing us.