You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. Can I know what help do you need from our agency?

USER: Please book a flight ticket from DFW to IAD?

ASSISTANT: Sure, I am happy to help you. Could you please help me by providing the travel dates?

USER: My journey dates are May 07 and May 09.

ASSISTANT: Ok, can you please tell me your requirement regarding the connection limit?

USER: I need a connecting flight.

ASSISTANT: On which name do you want me to book the ticket?

USER: I am Sarah Lee.

ASSISTANT: Is there any other specifications?

USER: No.

ASSISTANT: Sorry to tell you that, there is no flight found in this route with the dates you have given.

USER: No problem, thank you for your information.

ASSISTANT: You are welcome. Thank you for choosing us.