You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

USER: Can you aid me to book my ticket from LAS to ORD?

ASSISTANT: Sure, can you please share me your travelling dates?

USER: My trip dates are Mar 15 and Mar 17 respectively.

ASSISTANT: Do you have any connection limit?

USER: I prefer for single connecting flight.

ASSISTANT: Is there any other specifications?

USER: My depart should be in the evening.

ASSISTANT: May I know your name?

USER: Betty Green here.

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

USER: Thank you for the help.

ASSISTANT: Thank you for reaching us.