You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: I am Justin Garcia. I want to meet my project manager at Dallas, please book my flight ticket from EWR to DFW.

ASSISTANT: Sure, I will help you to book a flight ticket. Can you please share me your travelling dates?

USER: Yes, I want to depart on Feb 13 and return back on Fen 15.

ASSISTANT: Do you have any specifications?

USER: I prefer to depart in the evening.

ASSISTANT: Sorry, no flights are available on your route.

USER: Sad to hear that. Anyway, thank you.

ASSISTANT: Welcome, have a nice day. Thank you for choosing us.