This property is used to set or change the margins of the document. All four margins (left, right, top, and bottom) are set using this property. Valid measurement options for this property are:
mm millimeters. cm centimeters. in inches. pt points, which is a way of measuring the font size. One point is 1/72 (one seventy-second) of an inch. pc picas, which is yet another way of measuring font size. One pica is equal to 12 points. px pixels, which is one screen element. The display you're looking at is comprised of thousands of individual dots, each of which can change in color and luminosity to achieve the desired image. Each of these dots is referred to as a pixel. ex x-height settings, which is the height of the font's lower case letter 'x'. em em setting, which is the normal height of the font. Millimeters, centimeters, inches, points, and picas are considered to be absolute lengths because you're specifying the exact size of the type.
Relative units such as em and ex are interpreted as references to the parent font size.
syntax:
document.all.elementID.style.margin = "value"
This Property is used to access attributes of the following:
style