You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: Gary Davis here.

ASSISTANT: How can I assist you at this moment?

USER: Can you book a flight ticket for my travel dates that is from 07 Feb to 09 Feb?

ASSISTANT: Sure, I am here to help you. Could you please provide your airport codes of journey?

USER: The airport codes are from LAS to DEN.

ASSISTANT: May I know your connection limit for this journey?

USER: I need a single connecting flight.

ASSISTANT: Do you have any class preference?

USER: No.

ASSISTANT: May I know your specific depart and arrival timings?

USER: I would like to depart in the evening time.

ASSISTANT: Do you have any airline preference?

USER: No, that is it.

ASSISTANT: Gary Davis, there are no flight services are available on this route on your provided dates.

USER: Ok, not a problem. Thank you.

ASSISTANT: Thank you for contacting us.