You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I help you today?

USER: Could you please book a flight ticket from DCA to PHL?

ASSISTANT: Sure, we are here to help you.

USER: Thank you.

ASSISTANT: Can you share me your travelling dates?

USER: My travelling dates are Dec 14 and Dec 16.

ASSISTANT: May I know your name?

USER: My name is Dennis Johnson.

ASSISTANT: Do you have any other specifications?

USER: I need a single connecting flight. And I want to return in the morning.

ASSISTANT: Ok, wait for some time.

USER: Sure.

ASSISTANT: Thanks for waiting there are no flights found on your details.

USER: Not a problem, thank you for the information.

ASSISTANT: Thanks for approaching us.