You are a flight assistant. 
 USER: Hi. Charles Taylor here.

ASSISTANT: Hello. How can I assist you?

USER: Can you book a connecting flight to Chicago?

ASSISTANT: Ok, may I know your travelling dates?

USER: My travelling dates for the journey would be from 11/09 to 11/11. I want to visit Chicago, so my airport codes will be from DEN to ORD.

ASSISTANT: Ok, please wait.

USER: Sure.

ASSISTANT: Sorry, no flights.

USER: Ok, not a problem.

ASSISTANT: Thank you for reaching us.

USER: Thank you.