var headerImages=new Array();
var headerCI=0;
var headerTarget=0;
var headerHidden=0;
var headerLeft=0;
var headerSpd=0;
var headerS;
var headerAutoSlide=0;
var headerAutoTO=10000;
var headerMaxSpd=100;
var headerMinSpd=10;
var headerZrychleni=20;
var headerZpomaleni=10;
var headerTimerI;
var headerPaused=false;

function headerInit()
{
 headerS=ge("slideshow_images");
 var imgs=headerS.getElementsByTagName("img");
 for(var i=0;i<imgs.length;i++)
 {
  var img=new headerImage(imgs[i]);
  headerImages[i]=img;
  img.object.className='moving';
 }
 headerCI=parseInt((docGetCk("hspos")));
 if(isNaN(headerCI))headerCI=0;
 headerPaused=parseInt(docGetCk("hspause"))==1?true:false;
 if(headerPaused){ge("pause").className="pause_stisknuto";}
 headerTarget=headerCI;
 headerPlaceImages(headerCI);
 headerAutoSlide=window.setInterval("if(!headerPaused)headerMove(1);",headerAutoTO);
 headerTimerI=window.setInterval("headerTimer();",25);
}

function headerPause()
{
 headerPaused=!headerPaused;
 docSetCk("hspause",headerPaused?1:0);
 return headerPaused;
} 


function headerPlaceImages(first){headerPlaceImages,0}
function headerPlaceImages(first,onehide)
{
 var w=0;
 var cnt=headerImages.length;
 if(onehide)
 {
  var hi=headerIP2R(first-1);
  var img=headerImages[hi];
  img.object.style.left="0px";
  w=img.width;headerLeft=w;headerHidden=1;
 }
 else
 {
  headerLeft=0;headerHidden=0;
 }
 headerS.style.left="-"+headerLeft+"px";

 for(i=first;i<first+cnt-(onehide?1:0);i++)
 {
  var a=i%cnt;
  var img=headerImages[a];
  img.object.style.left=w+"px";
  w+=img.width;
 }
}

function headerMove(direction)
{
 window.clearInterval(headerAutoSlide);
 if(direction==-1)
 {
  headerTarget=headerIP2R(headerTarget-1);
 }
 else
 {
  headerTarget=headerIP2R(headerTarget+1);
 }
 docSetCk("hspos",headerTarget);
 headerTimer();
 headerAutoSlide=window.setInterval("if(!headerPaused)headerMove(1);",headerAutoTO);
}

function headerTimer()
{
 window.clearInterval(headerTimerI);
 var ht=headerTarget<headerCI?headerTarget+headerImages.length:headerTarget;
 var dif=ht-headerCI;
 var change=false;
 var dif2=headerImages.length-dif;
 if(dif2<dif)dif=-dif2;
 if(dif==0 && headerLeft>0)
 {
  headerCI=headerIP2R(headerCI+(headerHidden?-1:1));
  headerSpd=(headerHidden?-15:15);
  change=true;
 }
 
 if(dif>0)
 {
  var fi=headerImages[headerCI];
  if(dif==1 && headerLeft>fi.width/2)
  {
   if(headerSpd>headerMinSpd)headerSpd-=headerZpomaleni;
  }
  else
  {
   if(headerSpd<headerMaxSpd)headerSpd+=headerZrychleni;
  }
  headerLeft+=headerSpd;
  if(headerLeft>fi.width)
  {
   headerCI=headerIP2R(headerCI+1);
   headerPlaceImages(headerCI);
   headerLeft=0;
   if(headerTarget-headerCI==0){headerSpd=0;headerLeft=0;}
  }
  else
  {
   headerS.style.left="-"+headerLeft+"px";
  }
  change=true;
 }
 else if(dif<0)
 {

  if(headerLeft==0 || headerHidden!=1){headerPlaceImages(headerCI,1);}

  var ci=headerIP2R(headerCI-1);
  var fi=headerImages[ci];
  if(dif==-1 && headerLeft<fi.width/2)
  {
   if(headerSpd<-headerMinSpd)headerSpd+=headerZpomaleni;
  }
  else
  {
   if(headerSpd>-headerMaxSpd)headerSpd-=headerZrychleni;
  }
  headerLeft+=headerSpd;
  if(headerLeft<=0)
  {
   headerCI=headerIP2R(headerCI-1);
   if(headerTarget-headerCI==0)
   {
    headerSpd=0;headerLeft=0;
    headerPlaceImages(headerCI);
   }
   else
   {
    headerPlaceImages(headerCI,1);
   }
  }
  else
  {
   headerS.style.left="-"+headerLeft+"px";
  }
  change=true;
 }
 else
 {
  headerSpd=0;
 }

 if(change)headerTimerI=window.setInterval("headerTimer();",25);
}

function docSetCk(id,value){document.cookie=id+"="+unescape(value);}
function docGetCk(id)
{
 var cks=document.cookie.split("; ");var its=id+"=";
 for(var i=0;i<cks.length;i++)
 {
  var ck=cks[i];
  if(ck.substring(0,its.length)==its)
  {
   return ck.substring(its.length);
  }
 }
 return false;
}
function headerIP2R(ipt){var res=ipt%headerImages.length;if(res<0){res+=headerImages.length;}return res;}
function headerPageLoaded(){headerInit();}
function ge(id){return document.getElementById(id);}
function headerImage(img){this.object=img;this.width=this.object.clientWidth;}

window.onload=headerPageLoaded;