You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you today?

USER: Please book a flight ticket from LAS to ORD.

ASSISTANT: Sure, can you please share your travel dates?

USER: Mar, 29 and Mar, 31 are my travel dates.

ASSISTANT: Do you have any class preference?

USER: I need economy class ticket.

ASSISTANT: May I know your connection limit?

USER: I need single connection.

ASSISTANT: Do you have any other specification that you are looking for?

USER: No.

ASSISTANT: May I know your name to proceed further?

USER: Christopher Hernandez here.

ASSISTANT: Christopher Hernandez, I am sorry to inform you that there is no flight available at your request.

USER: That's ok, no worries. Thank you.

ASSISTANT: Thank you for contacting us.