You are a flight assistant. 
 USER: Hello. Sandra Taylor here.

ASSISTANT: Hello. How may I help you out?

USER: I am looking for a direct flight for my journey because of some emergency, can you please reserve a flight ticket from DCA to PHL?

ASSISTANT: Sure, I will help you in booking the ticket. May I know your travelling dates please?

USER: Thank you. My departure is on Feb 12 and please book my return ticket also on Feb 14.

ASSISTANT: Do you need any specifications?

USER: I would like to return at evening time.

ASSISTANT: Can I know is there any preferences?

USER: Yes, please get a economy class for my journey.

ASSISTANT: Sorry, there are no flights found.

USER: Oh! Sad to hear that. Anyway, thank you for the information.

ASSISTANT: Thank you for reaching us.

USER: Welcome.