adobe illustrator - How to avoid decimals on position and size using pixels

I am using Adobe Illustrator CS6 to create small images (like icons) for my app so I need pixel precision.

How can I avoid X, Y, W and H properties to have decimals? Can I configure 0 decimals for this properties on my document?

If I use the textboxes with this properties it does right, it increases pixel by pixel, but when draggin with the mouse it uses up to 3 decimals.

Answer

Select the object and then tick the Align to Pixel Grid option on the Transform Panel.

This will force objects to snap to the nearest pixel. So, beware, paths will move and changes to match the pixel grid. And strokes are limited to nothing less than 1pt/px.

When creating a new document, you can also choose the option to Align New Objects to Pixel Grid in the New Document dialog window. You can also choose the Align New Objects to Pixel Grid item in the Transform Panel menu to make all newly created objects have the option set by default.