CSS Need background image help with my css file

On my site I have a template that runs down the middle of the page (like free website templates) which my text, menus, and header hover over. That's fine.

However, the outer sides (left and right) are a dark blue color. I want to change the color to a background image, again - like free website templates with the blue lines on the sides.

How can I accomplish this? All I can seem to do is get it to be a color which is currently set at #213843.

The line I know needs to be adjusted is at the top in my css file and under "body" and is:
background: #213843 url(../images/template_images/containerbg.gif) repeat-y center;

The url image is fine and is the image used to put my text over, the #213843 is the entire page background color. That is what I want to change into an image.

Any clues how? I'm stumped.

Thanks

Site: http://www.eventurebiz.com
CSS: http://www.eventurebiz.com/styles/style.css

 

Thought I'd bump your post up and mention validation of code even though I am aware of the fact that some errors seem (and some times are) to be acceptable - and - you may already know -

To help validate - css - xhtml/html - rss feed - links - section 508 - WAI and speed

 

Thanks for the reports. I've been going over them. A few like you said are acceptable, but a few others I don't dare touch as I don't want to mess anything up.

I really appreciate your time. I'm still looking in on the info you provided.