function setcss() {
  if (screen.height > 900) {
    document.write("<link rel=stylesheet type=text/css href=fileadmin/tmpl/css/main.css />");
  }
  if (screen.height <= 900) {
    document.write("<link rel=stylesheet type=text/css href=fileadmin/tmpl/css/main_01.css />");
  }
}