You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you today?

USER: I am Margaret Wright. Can you help me in booking a ticket from DEN to ORD?

ASSISTANT: Sure, can you please help me with your travel dates?

USER: My planning dates are from 12/19 to 12/21.

ASSISTANT: Ok, let me check for the availability of flight.

USER: Sure, take your time.

ASSISTANT: Margaret, there is no flight available at your requested dates.

USER: That's fine, thank you for your help.

ASSISTANT: Thank you for contacting us.