You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you now?

USER: I would like to book a ticket from PHL to DFW, can you please help me out?

ASSISTANT: Sure, I am happy to help you with that. Can I have your travel dates please?

USER: I am travelling on these dates April 21st and 23rd.

ASSISTANT: Ok, please let me know your good name.

USER: Gregory Mitchell here.

ASSISTANT: Ok, please let me know your preferable timings of your journey.

USER: I prefer departure in the evening and return in the evening.

ASSISTANT: Do you have any other specifications?

USER: I need single connected flight.

ASSISTANT: Sorry to inform you that no flight is available to you on your planned dates.

USER: Ok no problem, thank you for your services.

ASSISTANT: Thank you  for choosing us.