var lightbox_bg,lightbox_box,lightbox_tip,lightbox_closer,lightbox_closertext,lightbox_tiptext,fotka;
var loadingImg="./loadingImg.gif";

function initLightbox()
{
  //odkazy
  for(i=0;i<document.images.length;i++)
  {
    if(document.images[i].parentNode.getAttribute("rel")=="lightbox") {document.images[i].onclick=otevriBox;}
  }
}
function setLightbox()
{
  //lightbox_bg
  lightbox_bg=document.createElement("div");
  lightbox_bg.setAttribute("id","lightbox_bg");
  lightbox_bg.onclick=zavriBox;
  //nastavení výšky overlaye
  if(document.body.offsetHeight<window.innerHeight) {lightbox_bg.style.height="100%";}
  else if(navigator.appName=="Microsoft Internet Explorer") {lightbox_bg.style.height=document.body.scrollHeight+"px";} 
  else {lightbox_bg.style.height=document.body.offsetHeight+"px";}
  document.body.appendChild(lightbox_bg);
  //lightbox_box
  lightbox_box=document.createElement("div");
  lightbox_box.setAttribute("id","lightbox_box");
  lightbox_box.onclick=zavriBox;
  lightbox_box.onmousemove=ukazTip;
  lightbox_box.onmouseout=skryjTip;
  document.body.appendChild(lightbox_box);
  //boxlightbox_tip
  lightbox_tip=document.createElement("div");
  lightbox_tip.setAttribute("id","lightbox_tip");
  lightbox_box.appendChild(lightbox_tip);
  //lightbox_closer
  lightbox_closer=document.createElement("div");
  lightbox_closer.setAttribute("id","lightbox_closer");
  lightbox_box.appendChild(lightbox_closer);
  //lightbox_closer text
  lightbox_closertext=document.createTextNode("×");
  lightbox_closer.appendChild(lightbox_closertext);
}
function otevriBox()
{
  setLightbox();
  lightbox_bg.style.display="block";
  var src=this.parentNode.getAttribute("href");
  var title=this.getAttribute("title");
  title=title?title:"";
  fotka=new Image();
  fotka.onload=ukazBox;
  fotka.src=src;
  function ukazBox()
  {
    lightbox_box.style.height=fotka.height+"px";
    lightbox_box.style.width=fotka.width+"px";
    if(navigator.appName=="Microsoft Internet Explorer") 
    {
      reg=new RegExp("MSIE [0-9]\.[0-9]");
      navigatorVerze=String(navigator.appVersion.match(reg));
      navigatorVerze=navigatorVerze.substring(5);
      navigatorVerze=parseInt(navigatorVerze);
      if(navigatorVerze<=6) {var y=(document.body.clientHeight-fotka.height)/2+document.body.scrollTop;}
      else{var y=(document.documentElement.clientHeight-fotka.height)/2+document.documentElement.scrollTop;}
    }
    else var y=(window.innerHeight-fotka.height)/2+window.pageYOffset;
    x=(document.body.clientWidth-fotka.width)/2;
    lightbox_box.style.left=x+"px";
    lightbox_box.style.top=y+"px";
    lightbox_box.style.backgroundImage="url('"+src+"')";
    //titulek
    lightbox_tiptext=document.createTextNode(title);
    lightbox_tip.appendChild(lightbox_tiptext);
    lightbox_box.style.display="block";
  }
  return false;
}
function zavriBox()
{
  lightbox_bg.style.display="none";
  lightbox_box.style.display="none";
  lightbox_tip.removeChild(lightbox_tiptext);
  fotka=null;
}
function ukazTip()
{
  lightbox_tip.style.display="block";
  lightbox_closer.style.display="block";
}
function skryjTip()
{
  lightbox_tip.style.display="none";
  lightbox_closer.style.display="none";
}