You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how best I can help you today?

USER: Can you help me to reserve a flight ticket from IAD to DTW?

ASSISTANT: Sure, On which dates would you like me to book a flight ticket for you?

USER: My trip dates are 30 July and 01 Aug.

ASSISTANT: Do you need direct flight or connecting flight?

USER: I need a direct flight.

ASSISTANT: For booking, we need your good name. Please mention it.

USER: I am William Martin.

ASSISTANT: Are there any more specifications for you?

USER: No.

ASSISTANT: Sorry to say that, there are no flights available on the routes of your journey.

USER: That's ok, thank you for giving information.

ASSISTANT: Thank you for availing us.