You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

USER: Can you please help me in booking the flight ticket from DCA to LAS?

ASSISTANT: Sure, please share me your travelling dates?

USER: I would like to travel on Mar 30 and return on Apr 01.

ASSISTANT: Do you have any class preference?

USER: I prefer business class.

ASSISTANT: is there any connection limit?

USER: I need connecting flight.

ASSISTANT: Do you have other specifications?

USER: I prefer normal cost airline.

ASSISTANT: May I know your name?

USER: Elizabeth Turner here.

ASSISTANT: Sorry, there were no flights with your given details.

USER: No problem, thank you for the information.

ASSISTANT: Thank you for reaching us.