<script type="text/javascript" src="select_css.js"> </script>

// select_css.js
  // -------------
  // select the appropriate stylesheet according to the user's screen resolution

  document.write("<link rel='stylesheet' type='text/css' href='");

  if (window.screen.height <= 600) {
    //resolution is 800x600 or less
    document.write("small.css'>");
  } else {
    document.write("large.css'>");
  }