You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I help you?

USER: Could you please book a flight ticket from ORD to DFW?

ASSISTANT: Sure, I am here to help you. Can you please let me know your travelling dates?

USER: My travelling dates are Dec 17 and Dec 19.

ASSISTANT: Is there any connection limit for you?

USER: I need  a single connecting flight.

ASSISTANT: Do you have any other specifications to be met?

USER: I want to depart in the afternoon and return  in the evening.

ASSISTANT: May I know your good name?

USER: I am Rebecca Hernandez.

ASSISTANT: Sorry, no flights are available on your journey routes.

USER: No problem, thank you for the information.

ASSISTANT: Thank you for contacting us.