You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you?

USER: I want to fly to Washington to visit Central Hall, can you help me to book a flight ticket with single connection?

ASSISTANT: Sure, may I know your source and destination airport codes please?

USER: My boarding and landing airport codes are ORD and DCA.

ASSISTANT: Can I have your planned trip dates please?

USER: I need to depart on Feb 5th and my return date will be on Feb 7th.

ASSISTANT: May I know your name please?

USER: I am Anthony Rodriguez.

ASSISTANT: Do you have any class preference?

USER: I need a business class ticket and i would like to fly with the normal cost airline.

ASSISTANT: Do you have any other preferences?

USER: No.

ASSISTANT: Anthony Rodriguez, no flights has been found on your requirements.

USER: No issues. Thank you for your information.

ASSISTANT: Thank you for approaching us.