You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Joseph Rodriguez.

ASSISTANT: How can I aid you today?

USER: I would like to depart in the evening from DCA, can you help me with booking ticket to LAS?

ASSISTANT: Sure, I am here to help you with that. Can I know your travelling dates?

USER: Ok, my planned dates are from Jan 03 to 05.

ASSISTANT: Do you have any other specifications?

USER: I want to return in the afternoon time with single connection.

ASSISTANT: Ok,do you have any other retirements?

USER: I need a flight in economy class.

ASSISTANT: Sorry to say that, there are no flight's available based on your travelling dates.

USER: It's ok, thanks for your information.

ASSISTANT: Thank you for reaching us.