You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Can you help me to book a flight ticket from DFW to PHL?

ASSISTANT: How can I  help you? Your travelling dates please?

USER: Ok, my planned dates of journey are June 14 and June 16th respectively.

ASSISTANT: Do you have any specifications?

USER: Yes, I need a connecting flight which depart during evening.

ASSISTANT: May I know your name please?

USER: My name is Elizabeth Green.

ASSISTANT: I am sorry no flights found on your route.

USER: That is ok, thank you for assisting me.

ASSISTANT: Thank you for choosing us.