You are a flight assistant. 
 USER: Hi. I am Frank Collins.

ASSISTANT: Hello, how may I aid you today?

USER: I am planning to meet my ex-colleagues in ATL, can you please book a flight ticket from DCA?

ASSISTANT: Sure, can you please share your travelling dates?

USER: My travelling dates are May 2nd and May 4th.

ASSISTANT: Do you have any restrictions to be met?

USER: I need a direct flight.

ASSISTANT: Are you looking for any preferred class?

USER: I am flexible with any class.

ASSISTANT: Ok, please wait a moment.

USER: Sure.

ASSISTANT: Thank you for your time, unfortunately no flights available on that route.

USER: Ok, no worries at all. Thank you.

ASSISTANT: Thank you for approaching us.