I'd suggest layout with CSS -but since you already started with tables, just use the first and last table cell in the first row of your table for your purple bar and make it a rowspan to cover all the rows of your table.
I'm designing a web site with two lateral bars that have the color theme of the site. I want this two bars to expand till the end of the page. I've tried using height="100%" but it's not a working option. Does anybody have any alternative solution?
the website is in www.starneuro.com/inicio.shtml and I want to expand the purple bars to cover 100% of the height of the page.
Thank You,
JMGB

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic