var img;
var nCurrIndex = 0;

var g_sAnimImgDiv;
var g_vCurr;
var g_nScroll;
function showimg(imgs, nIndex)
{
    g_nScroll = getScrollY();
    eBody = document.getElementById('wrapper');
    eBody.style.display='none';

    g_vCurr = imgs;
    clearInterval(g_nIntervalId);
    document["mainimg"].src = "./images/nothing.gif";

    display_img(imgs, nIndex);
}

function display_img(imgs, nIndex)
{
    eLoader = document.getElementById('img_loader');
    eLoader.style.display='block';

    if( nIndex < 0 ) nIndex = imgs.length - 1;
    if( nIndex >= imgs.length ) nIndex = 0;

    nCurrIndex = nIndex;

    //ładujemy obrazek
    img = new Image();
    img.src = imgs[nIndex];
    img.onerror = preloadOnError;

    g_sAnimImgDiv = document.getElementById('dlg');

    eDsc1Div = document.getElementById('img_desc1');
    eDsc1Div.innerHTML = "Zdjęcie " + (nIndex + 1) + "/" + imgs.length

    if( g_nImgOpacity == 0 )
    {
        g_sAnimImgDiv.style.opacity = 0;
        g_sAnimImgDiv.style.filter = 'alpha(opacity=0)';
    }

    g_sAnimImgDiv.style.display='block';

    if(g_nImgOpacity < 1)
            g_nIntervalId = window.setInterval("animImg()", 50);
    else
            preloadCheck();
}

var g_nIntervalId;
var g_nImgOpacity = 0;

function animImg()
{
    if( g_nImgOpacity < 1 )
    {
        g_nImgOpacity = g_nImgOpacity + 0.2;
        g_sAnimImgDiv.style.opacity = g_nImgOpacity;
        g_sAnimImgDiv.style.filter = 'alpha(opacity='+ (g_nImgOpacity) * 100 +')';
    }
    else
    {
        clearInterval(g_nIntervalId);
        preloadCheck();
    }
}

function animImg2()
{
    if( g_nImgOpacity >= 0 )
    {
        g_nImgOpacity = g_nImgOpacity - 0.3
        g_sAnimImgDiv.style.opacity = g_nImgOpacity;
        g_sAnimImgDiv.style.filter = 'alpha(opacity='+ (g_nImgOpacity) * 100 +')';
    }
    else
    {
        clearInterval(g_nIntervalId);
        g_sAnimImgDiv.style.display='none';

        eBody = document.getElementById('wrapper');
        eBody.style.display='block';

        window.scrollTo(0,g_nScroll);
    }
}

function closeImgViev()
{
    g_nIntervalId = window.setInterval("animImg2()", 50);
}

function preloadOnError()
{

}

function preloadCheck()
{
    if( img.complete )
    {
        document["mainimg"].src = img.src;

        eLoader = document.getElementById('img_loader');
        eLoader.style.display='none';
    }
    else
    {
        setTimeout('preloadCheck()',200);
    }
}


function imgPrev()
{
    display_img(g_vCurr, --nCurrIndex);
}
function imgNext()
{
    display_img(g_vCurr, ++nCurrIndex);
}

function getScrollY()
{
  var scrOfX = 0, scrOfY = 0;
  if( typeof( window.pageYOffset ) == 'number' )
  {
    //Netscape compliant
    scrOfY = window.pageYOffset;
    scrOfX = window.pageXOffset;
  } 
  else if( document.body && ( document.body.scrollLeft || document.body.scrollTop ) )
  {
    //DOM compliant
    scrOfY = document.body.scrollTop;
    scrOfX = document.body.scrollLeft;
  }
  else if( document.documentElement && ( document.documentElement.scrollLeft || document.documentElement.scrollTop ) )
  {
    //IE6 standards compliant mode
    scrOfY = document.documentElement.scrollTop;
    scrOfX = document.documentElement.scrollLeft;
  }
  return scrOfY;
}

function keyDownHandler(e)
{
    if( g_nImgOpacity == 0 )
        return;
    
      var kC  = (window.event) ?    // MSIE or Firefox?
                 event.keyCode : e.keyCode;
      var Esc = (window.event) ?
                27 : e.DOM_VK_ESCAPE // MSIE : Firefox
            
    if(kC==Esc)
         closeImgViev();
    else if(kC == 39 )
         imgNext();
    else if( kC == 37 )
         imgPrev();
}