function zs(idecko){
  el=document.getElementById(idecko).style;
  el.display=(el.display == 'block')?'none':'block';
}

function sz(idecko){
  el=document.getElementById(idecko).style;
  el.display=(el.display == 'none')?'block':'none';
}

function styp(idecko){
  if(idecko == 'zbytekodkaz') {
    document.getElementById('zbytek').style.display = 'block';
    document.getElementById('zbytekodkaz').style.display = 'none';
  }
  if(idecko == 'doutniky') {
    document.getElementById('doutniky').style.display = 'block';
    document.getElementById('prislusenstvi').style.display = 'none';
  } else {
    document.getElementById('doutniky').style.display = 'none';
    document.getElementById('prislusenstvi').style.display = 'block';
  }
}

function externalLinks() {
  if (!document.getElementsByTagName) return;
  var anchors = document.getElementsByTagName("a");
  for (var i=0; i<anchors.length; i++) {
   var anchor = anchors[i];
   if (anchor.getAttribute("href") &&
       anchor.getAttribute("rel") == "external")
     anchor.target = "_blank";
  }
}