How do I add 1px border to a div whose width is a percentage?

Question

I have this jsfiddle http://jsfiddle.net/tara_irvine/DZLTJ/1/ which explains my problem.

I want the menu items along the top to be 20% of the window but I also want

Answer 1

For the border, you can use

outline: 1px solid black;

this works on all modern browsers, but not on IE6 and 7