You can make divs, margins and padding in % widths but borders cannot be %, so if you have side borders you may have to make the total widths add up to 98% or 99% to allow for the px borders.
You can also size images in %, if you only give a % width and don't size the height, the height will resize in proportion, but that may create height you don't want and disrupt the layout.
Code downloaded to my PC will be deleted in due course.
WIN7; IE9, Firefox, Opera, Chrome and Safari for Windows; screen resolution usually 1366*768.
Also IE6 on W98 with 800*600 and IE8 on Vista 1440*900.