eta name="assert" content="When 'top', 'bottom' and 'height' are all are not 'auto', 'margin-top' is not 'auto' and 'margin-bottom' is 'auto'. Then 'margin-bottom' becomes the remainder of the height of the containing box." />
        <style type="text/css">* { margin: 0; padding: 0 }
            #div1
            {
                border: solid black;
                height: 3in;
                position: relative;
                width: 3in;
            }
            div div
            {
     