function otworz_zdjecie(src)
{
  galeriaduze.src=src;
}

function getDocumentWidth()
{
  if (document.body.scrollWidth)
    return document.body.scrollWidth;
  var w = document.documentElement.offsetWidth;
  if (window.scrollMaxX)
    w += window.scrollMaxX;
  return w;
}

function getScrollXY() {
  var scrollX = 0, scrollY = 0;
  if( typeof( window.pageYOffset ) == 'number' )
	{
    scrollY = window.pageYOffset;
    scrollX = window.pageXOffset;
	}
	else if( document.body && ( document.body.scrollLeft || document.body.scrollTop ) )
	{
    scrollY = document.body.scrollTop;
    scrollX = document.body.scrollLeft;
  }
	else if( document.documentElement && ( document.documentElement.scrollLeft || document.documentElement.scrollTop ) )
	{
    scrollY = document.documentElement.scrollTop;
    scrollX= document.documentElement.scrollLeft;
  }
  return [scrollX, scrollY];
}

function getDocumentHeight()
{
  if (document.body.scrollHeight)
    return document.body.scrollHeight;
  return document.documentElement.offsetHeight;
}

function pozycjonowanie()
{
	var x = 0, y = 0;
  if( typeof( window.innerWidth ) == 'number' )
	{
    x = window.innerWidth;
    y = window.innerHeight;
  }
	else if( document.documentElement && ( document.documentElement.clientWidth || document.documentElement.clientHeight ) )
	{
    x = document.documentElement.clientWidth;
    y = document.documentElement.clientHeight;
  }
	else if( document.body && ( document.body.clientWidth || document.body.clientHeight ) )
	{
    x = document.body.clientWidth;
    y = document.body.clientHeight;
  }
	divor.style.width = document.getElementById("mainc").offsetWidth + "px";
	divor.style.height = document.getElementById("mainc").offsetHeight + 50 + "px";
	divor.style.left = document.getElementById("mainc").offsetLeft +"px";
	if ((x-galeriaduze.width)/2 > 50) galeriaduze.style.left=(x-galeriaduze.width)/2 + "px";
		else galeriaduze.style.left= "50px";
	if ((y-galeriaduze.height)/2 > 50) galeriaduze.style.top=(y-galeriaduze.height)/2 + document.body.scrollTop + getScrollXY()[1] + "px";
		else galeriaduze.style.top = getScrollXY()[1] + 50 + "px";
}

function zamknij_zdjecie()
{
  divor.style.visibility = "hidden";
  galeriaduze.style.visibility = "hidden";
  galeriaduze.src = "";
	paused = false;
}

function loaded()
{
  pozycjonowanie();
  divor.style.visibility="visible";
	galeriaduze.style.visibility = "visible";
	paused = true;
}

function set_opacity(opacity)
{

  document.getElementById("photo").style.opacity = opacity/100;
	document.getElementById("photo").style.filter = "alpha(opacity=" + opacity + ")";
}

function mouse_over()
{
  hovered = true;
}

function mouse_out()
{
  hovered = false;
}

function click()
{
  otworz_zdjecie("gfx/photo/" + activephoto + "b.jpg");
}

function main()
{
  if (hovered == true || paused == true)
	{
	  op = 100;
		ud = "d";
	  set_opacity(op);
		setTimeout("main()", steptime);
	}
	else
	{
  	if (ud == "d")
	  {
	    if (op > 0)
	    {
        setTimeout("set_opacity(op)", steptime);
			  setTimeout("main()", steptime);
	      op-=step;
    	}
    	else
    	{
	      ud = "u";
	  		if (activephoto == photocount) activephoto = 1;
	  		else activephoto++;
	  		document.getElementById("photo").src = "gfx/photo/" + activephoto + ".jpg";
        setTimeout("set_opacity(op)", steptime);
	  		setTimeout("main()", steptime);
  	  }
	  }
  	else
	  {
	    if (op < 100)
	  	{
        setTimeout("set_opacity(op)", steptime);
		  	setTimeout("main()", steptime);
				op+=step;	   
	  	}
	  	else
	  	{
	  		ud = "d";
        setTimeout("set_opacity(op)", time);
	  		setTimeout("main()", time);
	  	}
	  }
	}
}

step = 2;
steptime = 20;
time = 2000;
photocount = 4;
divorop = 70;

ud = "u";
hovered = false;
paused = false;
op = 100;
activephoto = 1;

var galeriaduze = document.createElement("img");
  galeriaduze.style.visibility = "hidden";
	galeriaduze.style.position = "absolute";
	galeriaduze.style.border = "3px solid #99e700";
	galeriaduze.style.margin = "0px auto";
	galeriaduze.style.cursor = "pointer";
	galeriaduze.onclick = zamknij_zdjecie;
	galeriaduze.onload = loaded;
var divor = document.createElement("div");
  divor.style.visibility = "hidden";
	divor.style.position = "absolute";
	divor.style.left = "0px";
	divor.style.top = "0px";
	divor.style.backgroundColor = "gray";
	divor.style.opacity = divorop/100;
	divor.style.filter = "alpha(opacity=" + divorop + ")";
document.body.appendChild(divor);
document.body.appendChild(galeriaduze);
if (window.addEventListener)
{
  window.addEventListener("scroll", pozycjonowanie, false);
  window.addEventListener("resize", pozycjonowanie, false);
}
else
{
  window.attachEvent("onscroll", pozycjonowanie);
  window.attachEvent("onresize", pozycjonowanie);
}
document.getElementById("photo").onmouseover = mouse_over;
document.getElementById("photo").onmouseout = mouse_out;
document.getElementById("photo").onclick = click;
main(op);