Expected results:
The first button should be exactly 60px wide
The second button should be 20% of the blue bordered paragraph's width: so it should be exactly 80px wide, regardless of the window size
The 3rd button should be exactly 90px wide
The 4th button should be 30% of the blue bordered paragraph's width which can change on a resize of the window

The stylesheet is as follows:
body {margin: 91px; padding: 0px; border: 4px solid red; color: black; background: white url("../../GRAPHICS/GIF/grid.gif");}
p {border: 5px solid blue;}
p#FirstParg , p#SecondParg {width: 400px;}
button#FirstButton {width: 60px;}
button#SecondButton {width: 20%;} /* so this button should be 80px wide */
button#ThirdButton {width: 90px;}
button#FourthButton {width: 30%;}

Valid HTML 4.01! CSS compliant