Can I hide an entire div, then unhide certain sections?

Hello to everyone, this is my first post here.

I'm creating a Java Script that will automatically activate a single stylesheet from a series of alternate stylesheets based on the width of the browser window. When I'm done I will post it for download as Freeware.

I'm trying to create a series of demo pages that do not use the script, but allow you to select each alternate stylesheet with a click of the mouse. Each of these pages should display some boiler plate stuff, but also a few different things based on which style sheet is active. Hope that was fairly clear.

My original thought on this was to key the variable stuff as follows:

<div ID=demo>
<p class=show1>This is the stuff for style 1</p>
<p class=show2>This is the stuff for style 2</p>
<p class=show3>This is the stuff for style 3</p>
</div>

Then I could create a screen.css file that included the line:

>#demo {display:none;}</code
 
Then create my alternate stylesheets style1.css, style2.css etc:
 
<code>@import url('screen.css');
#demo.show1 {display:inline;}

My original thought was that the #demo.show1 would be more specific and would therefore override the display none in the screen.css. Doesn't seem to work that way.

Is there a way to do something like this?

The alternative would be to define style1.css with entries to display none everything but the show1 lines. This can be a hassle as I add more and more examples and have to go back and update each of the existing css files. That is why I was looking for a way to basically hide all of them, then unhide the one I want for each example.

Hope this isn't too much for my first post, and I hope I'm not overstepping my bounds talking about the script I'm writing, like I said, it will be freeware when it's done.

The concept for the script would be to treat the displayed page the same as the way we use css to create a printable page, hiding certain items so the page is narrow enough to print.

I am also on the web design forum as PapaGeek where I ask the more technical questions about scripting.