var bIe=navigator.userAgent.indexOf("MSIE")!=-1 && document.all && !window.innerWidth;
var bMz=navigator.userAgent.indexOf("Gecko")!=-1 && document.getElementById && !document.all;
var bOp=navigator.userAgent.indexOf("Opera")!=-1 && document.getElementById ? 1:0;
var bKn=navigator.userAgent.indexOf("Konqueror")!=-1 && document.getElementById && document.body.offsetWidth ? 1:0;
var bNs=navigator.userAgent.indexOf("Opera")==-1 && document.getElementById && !document.all;
var bOp6=bOp && document.body.offsetWidth ? 1:0;
var bNs4=document.layers ? 1:0;

// promenny pro slideshow 
var timer = null;
var timerblinder = null;
var timerwait = null;
var slideshowtimer = 2500;
var blindertimer = 20;
var blindersteps = 25;

// dopocitany promenny
var actualstep = 1;
var switched = false;
var switchingstep = blindersteps / 2;
var step = 3.1415926/blindersteps;

function get_element(a) {
  return(bIe ? document.all[a]:bNs4 ? document.layers[a]:document.getElementById(a));
}

function changeheader(trida) {
  obj = get_element('header');
  obj.className = trida;

  obj = get_element('lart');
  obj.className = trida;

}

function changedefault() {
  obj = get_element('lart');
  if (obj != null) {
    obj.className = null;
  }

}

function startslideshow(delay) {
  timer = setInterval("shownext(true)",delay);
}

function stopslideshow() {
  if (timerblinder == null) {
    clearInterval(timer);
    timer = null;
    if (timerwait != null) {
      clearInterval(timerwait);
      timerwait = null;
    }
  }
  else {
    if (timerwait == null) {
      timerwait = setInterval("stopslideshow()",blindertimer);
    }
  }
}

function defocus() {
  if (bIe) window.focus();
  else {
    obj = get_element('focus');
    if (obj != null) {
      obj.focus();
    }
  }
}

function switchimage(imageid,cont) {

  i = 1;

  do {
    id = 'img' + i;
    idm = 'mnu' + i;

    img = get_element(id);
    mnu = get_element(idm);
    
    if (img != null) {
      if (imageid != i) { // nastavit nepruhlednost
        img.style.display = 'none';
        mnu.className = 'mnu';
      }
      else {
        img.style.display = 'block';
        mnu.className = 'mnusel';
      }
    }
    i++;
  }
  while (img != null);

}

function showukazka(imageid,cont) {

  // vypnuti slideshow, pokud bezi.. pak ji ale zase zapnu
  if (cont) {
    if (timer != null) stopslideshow();
  }
  else {
  	if ((timer != null) || (timerblinder != null)) toggleslideshow();
  }
  
  actualstep = 1;
  switched = false;
  if (timerblinder != null) clearInterval(timerblinder);
  timerblinder = setInterval("blinder("+imageid+","+cont+")",blindertimer);
  
  if (!cont) defocus();

}

function setopacity(idi,opacity) {
	obj = get_element(idi);
  if (obj != null) {

    // pro IE
    if (bIe) {
	    obj.style.filter = 'alpha(opacity=' + opacity + ')';
    }

	  // pro ostatni
	  else {
      value = (opacity >= 100) ? 1 : '.'+opacity;
      obj.style.opacity = value;
      // obj.style.moz-opacity = value;
	  }
  	
  }
}

function blinder(imageid,cont) {

	if (actualstep <= blindersteps) {

    changed = false;

    // pripadne prehozeni obrazku
		if (!switched) {
		  if (actualstep >= switchingstep) {
        setopacity('blinder',100);
		  	switchimage(imageid,cont);
		  	switched = true;
		  	changed = true;
		  }
		}
		
		// zmena opacity normalnim zpusobem
		if (!changed) {
      faze = Math.sin(actualstep*step);
			opacity = Math.round(faze * 100);
			setopacity('blinder',opacity);
		}
		
	}
	else { // ukoncit akci

    // nastavit opacity na 0
    setopacity('blinder',0);
		
		// pustit slideshow
		if (cont) startslideshow(slideshowtimer);
		
    // zrusit blindovani
		clearInterval(timerblinder);
    timerblinder = null;
		
	}

	actualstep++;

}

function hideukazka() {
  obj = get_element('ukazka');
  obj.style.left = '-9999px';
}

function shownext(cont) {

  selected = 0;
  i = 1;
  do {
    id = 'mnu' + i;
    mnu = get_element(id);
    if (mnu != null) {
      if (mnu.className == 'mnusel') selected = i;
    }
    i++;
  }
  while (mnu != null);
  max = i-2;
  
  // next
  if (selected < max) showukazka(selected+1,cont);
  else showukazka(1,cont);

  if (!cont) defocus();
}

function showprev(cont) {

  selected = 0;
  i = 1;
  do {
    id = 'mnu' + i;
    mnu = get_element(id);
    if (mnu != null) {
      if (mnu.className == 'mnusel') selected = i;
    }
    i++;
  }
  while (mnu != null);
  max = i-2;
  
  // prev
  if (selected > 1) showukazka(selected-1,cont);
  else showukazka(max,cont);

  if (!cont) defocus();
}

function showpage(pageid) {

  i = 1;
  sel = ((pageid - 1) * 3) + 1;

  do {
    id = 'row' + i;
    idm = 'mnu' + i;

    row = get_element(id);
    mnu = get_element(idm);
    
    if (row != null) {
      if ((i == sel) || (i == (sel + 1)) || (i == (sel + 2))) row.style.display = 'block';
      else row.style.display = 'none';

      if (mnu != null) {
        if (i == pageid) mnu.className = 'mnusel';
        else mnu.className = 'mnu';
      }
    }
    i++;
  }
  while (row != null);

  window.focus();
}

function shownextpage() {

  selected = 0;
  i = 1;
  do {
    id = 'mnu' + i;
    mnu = get_element(id);
    if (mnu != null) {
      if (mnu.className == 'mnusel') selected = i;
    }
    i++;
  }
  while (mnu != null);
  max = i-2;
  
  // next
  if (selected < max) showpage(selected+1);
  else showpage(1);

  window.focus();
}

function showprevpage() {

  selected = 0;
  i = 1;
  do {
    id = 'mnu' + i;
    mnu = get_element(id);
    if (mnu != null) {
      if (mnu.className == 'mnusel') selected = i;
    }
    i++;
  }
  while (mnu != null);
  max = i-2;
  
  // prev
  if (selected > 1) showpage(selected-1);
  else showpage(max);

  window.focus();
}

function calcheight(options,showinfo) {

  // nastaveni sirky obrazu, podle obrazku, ale jen, pokud je sirsi, nez 954
  // vsechny obrazky maji stejneou sirku..
  id = 'img1';
  img = get_element(id);
    
  if (img != null) {

    sirka = img.offsetWidth;
    vejska = img.offsetHeight;
    
    if (sirka > 954) {
      idl = 'lart_lista_ukazky';
      obj = get_element(idl);
      if (obj != null) {
        obj.style.width = sirka + 'px';
      }
    }

    idb = 'blinder';
    obb = get_element(idb);
    idf = 'focus';
    obf = get_element(idf);
    if (obb != null) {
      if (sirka < 954) obb.style.width = '954px';
      else obb.style.width = sirka + 'px';
      obb.style.height = vejska + 'px';
    }
    if (obf != null) {
      if (sirka < 954) obf.style.width = '954px';
      else obf.style.width = sirka + 'px';
      obf.style.height = vejska + 'px';
    }
  }

  // pripadne zobrazeni infa
  if (showinfo == 'false') {
    initinfo();
    // toggleinfo();
  }

  // nastaveni vejsek vsech boxiku
  max = 0;
  box1 = get_element('zadani');
  if (box1 != null) max = box1.offsetHeight;
  
  box2 = get_element('cil');
  if ((box2 != null) && (box2.offsetHeight > max)) max = box2.offsetHeight;

  box3 = get_element('vysledek');
  if ((box3 != null) && (box3.offsetHeight > max)) max = box3.offsetHeight;
  
  obj = get_element('pozadi');
  if (obj != null) obj.style.height = max+36 + 'px';

  mnu = get_element('mnuinfo');
  obj = get_element('projekt_info');
  if ((mnu != null) && (obj != null)) mnu.className = (obj.offsetLeft == '18') ? 'infosel' : 'info';

  // pripadne nastartovani slideshow
  if (options != 'dontslide') startslideshow(slideshowtimer);
  else {
    obj = get_element('mnuslide');
    if (obj != null) {
      obj.className = 'slide';
      obj.innerHTML = '<strong>play</strong>';
    }
  }
}

function initinfo() {
  obj = get_element('projekt_info');
  if (obj != null) {
    obj.style.left = '-9999px';
    mnu = get_element('mnuinfo');
    if (mnu != null) mnu.className = 'info';
  }
  defocus();
}

function toggleinfo() {
  obj = get_element('projekt_info');
  if (obj != null) {
    obj.style.left = (obj.offsetLeft == '18') ? '-9999px' : '18px';
    mnu = get_element('mnuinfo');
    if (mnu != null) mnu.className = (obj.style.left == '18px') ? 'infosel' : 'info';
  }
  defocus();
}

function toggleslideshow() {

  obj = get_element('mnuslide');

  if ((timer != null) || (timerblinder != null)) {  // vypnout slideshow

    if (obj != null) {
      obj.className = 'slide';
      obj.innerHTML = '<strong>play</strong>';
      stopslideshow();
    }
  }
  else {  // zapnout slideshow
    if (obj != null) {
      obj.className = 'slidesel';
      obj.innerHTML = '<strong>stop</strong>';
      startslideshow(slideshowtimer);
    }
  }

  defocus();
}