Full viewport height scaling div just css no js... Possible?

Question

Ok, I'm trying to get a div to scale and the height is always the height of the viewport. I'm going to link to my examples as it needs some explaining.

www.madmediablitz.com/tv/precentdemo.html

The link above is the closest I've come to a solution and I'm hoping that someone here will find it simple to fix. What I want to happen is the tv to always be the height of the viewport (to a degree, min-height:~400px; max-height:~700px;). The code that I used there is based on http://www.alistapart.com/articles/creating-intrinsic-ratios-for-video/.

www.madmediablitz.com/tv/precentdemo_alt.html

This one is what I DON'T want to happen. IF you resize your window you will see it doesn't scale proportionally.

I've been trying both of these for about 2 days now and I haven't been able to get it to work. I'm literally praying for help as I think, this isn't too complicated.

Answer 1

Please see this: http://stanhub.com/how-to-make-div-element-100-height-of-browser-window-using-css-only/

<div id="welcome">
   your content on screen 1
</div>

<div id="projects">
   your content on screen 2
</div>
div#welcome {
    height: 100vh;
    background: black;
}

div#projects {
    height: 100vh;
    background: yellow;
}

That's it.