You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you today?

USER: I am Paul White. I want to meet my friend in Washington, can you please help me in booking a flight ticket?

ASSISTANT: Sure. Could you provide your travel dates?

USER: My planning dates are from 06/09 till 06/11.

ASSISTANT: Will put forward your airport codes?

USER: I want to fly from DTW to IAD.

ASSISTANT: Please, give me a minute.

USER: Ok, take your time.

ASSISTANT: Sorry, there are no flights available to your destination point.

USER: It's ok, thank you for checking.

ASSISTANT: Thank you for choosing us, hope we serve you next time.