You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I aid you?

USER: Please book me a ticket from DCA to PHL.

ASSISTANT: Sure, we are mirthful to help you. On which dates would you like me to book a flight ticket for you?

USER: I will start on Feb 19th and return on Feb 21st.

ASSISTANT: Do you need any connections between your trip?

USER: I need 1 stop over.

ASSISTANT: May I know your name?

USER: I am Amanda Lopez.

ASSISTANT: Do you need any other requirements?

USER: No.

ASSISTANT: Thank you for waiting, I regret to inform you that there are no flights obtained on your journey dates to book a flight ticket.

USER: That's alright, thanks for your assistance.

ASSISTANT: Thank you for contacting us.