You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I assist you today?

USER: I want to reserve my ticket from DEN to ORD, can you please help me in reserving my ticket?

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

USER: Sure, my planned dates of journey are from May, 18 to May, 20.

ASSISTANT: May I know your connection limit?

USER: Yes, I want to fly in a connecting flight.

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

USER: Yes, I want to travel in a business class.

ASSISTANT: May I know your name to proceed further?

USER: Sure, my name is Charles Hernandez.

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

USER: Ok, no problem. Anyways, thank you for your service.

ASSISTANT: Thank you for contacting us.