You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you today?

USER: I want to book a flight ticket from EWR to DEN to meet my friend. Can you help me in booking a direct flight?

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

USER: My journey dates are Aug 21 and Aug 23.

ASSISTANT: Any other requirements to be met?

USER: I am looking for a return flight time at afternoon.

ASSISTANT: May I know your name please?

USER: I am Melissa Williams.

ASSISTANT: Sorry, there are no flights found with your given details.

USER: No problem, thank you for your information.

ASSISTANT: Thank you for opting us.