Intellegent design, and How I am not doing it

I want to fix my column levels

[Baruch Menachem]

Right now my CSS has a wrapper class of 1000px
Inside of that is
A right sidebar width of 21%
and a discussion section of 70%

Inside discussion there are sometimes
rtext and ltext of 47% each.

Would it be smarter to do wrapper of 96% (I have a body color style that makes a nice color border)
and have absolute values of 210 for the right sidebar, 700 for discussion and have an absolute value for rtext and no value for ltext? The question is best practice, not what would work better in this instance.
When are absolute values better, when are percentages better?

[londrum]

absolute values are probably easier, but could give you major headaches if you ever want to display something underneath the columns (like a footer).
percentages are usually better because you can scale the page to whatever screen size you want. a 210px column might end up looking too small or too big on different size screens.
i would only ever pick a fixed size for a column if i knew it definitely had to contain something of that width (like a 160px advert)

1000px is a bit of a strange figure to pick for a wrapper though. you'll end up with horizontal scrollbars on most screens, and blank space on the bigger screens.