You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I help you today?

USER: I am David Hill. I need to book a flight ticket from ORD to DCA, Can you please help me for booking?

ASSISTANT: Sure Hill, may I know your dates of journey please?

USER: I would like to travel on 06/01 to return on 06/03.

ASSISTANT: Do you have any other requirements please?

USER: I need a connecting flight.

ASSISTANT: May I know your class preference please?

USER: I need a economy class.

ASSISTANT: Please wait for a moment.

USER: Sure.

ASSISTANT: Sorry Hill, there is no flight found as per your travelling details.

USER: Ok, no problem. Thanks for your information.

ASSISTANT: You are welcome.