window.onresize = reswid;
window.onload = reswid; //toto je prvni onload event

function reswid() {
  var windowHeight;
  if (self.innerHeight) {windowHeight = self.innerHeight;} // all except Explorer
  else if (document.documentElement && document.documentElement.clientHeight) {windowHeight = document.documentElement.clientHeight;} // Explorer 6 Strict Mode
  else if (document.body) {windowHeight = document.body.clientHeight;} // other Explorers

  if (windowHeight<620) {
  document.getElementById('h1head').style.display = "none";
  }
  else {
  document.getElementById('h1head').style.display = "block";
  }

  if (windowHeight<560) {
//  document.getElementById('t_col').style.display = "none";
//  document.getElementById('b_col').style.display = "none";
  // nacti extra CSS
  var extraCSS = document.createElement("link")
  extraCSS.href = "/css/os_reswid1100color.css";
  extraCSS.type = "text/css";
  extraCSS.rel = "stylesheet";
  extraCSS.media = "screen";
  document.getElementsByTagName("head")[0].appendChild(extraCSS);
  }
  else {
//  document.getElementById('t_col').style.display = "block";
//  document.getElementById('b_col').style.display = "block";
  }
}