You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, what can I do for you today?

USER: Could you please help me to book an economy class ticket from Dallas to meet my old friend to start a new business in Chicago?

ASSISTANT: Sure, when you want to travel?

USER: Sure, I want to start my journey on Dec 3rd and my return date will be on Dec 5th.

ASSISTANT: Do you have any other preferences?

USER: I would like to fly with the connecting flight for this time.

ASSISTANT: Ok, on which name should I book the ticket?

USER: I am Mark Anderson.

ASSISTANT: Sorry, no flights found as per your requirements.

USER: That's ok, I'll choose any alternative to reach my destination. Thank you for your information.

ASSISTANT: Thank you for contacting us.