When was the last time you saw a “resized-pop-up window” with full chrome ? Nowadays, everyone is using modal pop-up windows/pop-in windows/Div layers/modal windows…whatever you call them, they are much better for web designers and basic usability.

What about the basic features of these faux-windows ?

Drop shadows are not just for looks, they help the window stand out from the background by reinforcing it’s dimensions. They also block out the noise of the content beneath the window by darkening the area around it. The shadow in the web design help the user focus his attention on the appearing window.

Close buttons are a must. I have seen some inexperienced users wonder what to do to close the window, do I click on it? Where’s the close button…so make sure that button is super-clear.