You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: Can you please help me to book a flight from DEN to DFW?

ASSISTANT: Please provide your travelling dates.

USER: Sure, I want to travel on Oct 28 and need to return on Oct 30.

ASSISTANT: Do you have any specification?

USER: I need a connecting flight.

ASSISTANT: May I know your name?

USER: Myself Jonathan Williams.

ASSISTANT: Sorry, there is no flight with your travelling dates.

USER: Ok, not an issue. Thank you for checking.

ASSISTANT: Thank you.