How do I get 3D edges?

How do I get 3D edges?
OK... so that might be a dumb question! :)
But... I wanted to know if there was some kind of design guide on how and when to add a small white line above a rectangle or something and giving it that subtle 3D look.

Any help would be appreciated!

Thanks.


Jam

Go here. Bottom left side, get the ColorPic and the Screen Calipers. They are both free and they are both small and work with every program I have with no conflict.

The colorpicker has a window that shows the color of the pixels under the mouse pointer. Set to 10X, 1000, it shows those 3D images the way the screen sees them, afterall, the screen is 2D. So go to a link with something you want to take a closer look at and open the ColorPic. ;)

When in flash, you can magnify the stage by 800% by clicking in the dropdown, but you can type in up to 2000 to magnify it more if you need to.

Here's an early fla to see how I did it.

Thanks for that. I'll try both of them out later.