You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I help you?

USER: I am Rebecca Miller want to book a flight ticket from Washington to Detroit, so can you please book me a direct flight?

ASSISTANT: Sure, do you have any price limit?

USER: Yes, I need a ticket with price under 500.

ASSISTANT: Help me with the source and destination codes?

USER: Sure, my airport codes are DC-DCA and MI-DTW.

ASSISTANT: Can you please share me your dates of travelling?

USER: Yes, my travelling dates are 08/14 and 08/16.

ASSISTANT: Please wait a moment.

USER: Ok.

ASSISTANT: There is no flight with your respective dates of travel.

USER: That's ok, thank you for the response.

ASSISTANT: Thank you for reaching us.