You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I help you?

USER: I would like to travel to DFW for business trip, can you please reserve a flight ticket from JFK?

ASSISTANT: Sure, may I know your trip dates please?

USER: Sure, my planned travelling dates are Jul, 26 and 28 respectively.

ASSISTANT: Do you have any other requirements?

USER: Yes, flight has to be with single connection.

ASSISTANT: Can I know your name please?

USER: Sure, my name is Benjamin Walker.

ASSISTANT: Sorry, we regret to inform you that there is no flight available as per your request.

USER: Ok, not an issue.Thank you for your information.

ASSISTANT: Most welcome.