var agent = navigator.userAgent.toLowerCase();
var isWindows = ((agent.indexOf("win") != -1) ||
                 (agent.indexOf("16bit") != -1));
var isMac = (agent.indexOf("mac") != -1);

if (isWindows) {
  // Load windows-specific fontspecs
  document.write('<'+'link rel="stylesheet" href="ic-win.css" />');
} else if (isMac) {
  // Use Windows fontspecs for Max as well
  document.write('<'+'link rel="stylesheet" href="ic-win.css" />');
} else {
  // Unix (esp. Linux) specific fontspecs
  document.write('<'+'link rel="stylesheet" href="ic-unix.css" />');
}