You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: Joseph Perez here.

ASSISTANT: How can I help you?

USER: I would like to prefer a single connecting flight to Dallas & Fort Worth. So can you book a flight ticket for me?

ASSISTANT: Sure, I will help you. May I know your itinerary dates?

USER: The travel dates are from Oct 28 to Oct 30.

ASSISTANT: May I know your airport codes?

USER: My airport codes are from EWR to DFW.

ASSISTANT: Is there any specifications?

USER: No.

ASSISTANT: Sorry, there are no flights found on your trip dates.

USER: Not a problem. Thank you.

ASSISTANT: Thank you for choosing us.