title: Calculating margin based on screen height
body: <p>I have an application with some smallish windows that are displayed in isolation - these windows look fine when viewed on a small screen, but on a large one they look awkwardly small (and perhaps more annoyingly, awkwardly positioned).</p>
  
  <p>Is there a way to have, say, a 0px margin-top if the screen height is less than 1000px, then increase that margin-top by 50% of any additional height beyond that?</p>
  
  <p>Most importantly, I only want to consider implementing something like this if it can work dependably cross-browser (some of my users will be as far back as IE7).</p>