var oLowerNav;
var aPics;
var iAll;
var oCurrent={};
var aTumbnails = [];
var iCurrent = 0;
var sTumbnailHiddenCN = 'hidden';
var sInvisibleClassName = 'invisible';
var oLeft;
var oRight;

function initimg()
{
	oLeft = document.getElementById('gallery-left');
	oRight = document.getElementById('gallery-right');
	oLowerNav = document.getElementById('slideshow');
	aPics = oLowerNav.getElementsByTagName('img');
	iAll = aPics.length;
	oCurrent = _getPicByIndex(iCurrent);
	if (oCurrent) 
		noImages = 1;
	for (var i=0; i<this.aPics.length; i++) 
	{
		aTumbnails.push(i);
		if (i == 2)
			break;
	}
	_updateThumbnailArr();
	_updateLeftRight();
	_pokazMiniaturki();
}
function _updateLeftRight2(i) 
{
	oLeft.className = '';
	oRight.className = '';
	if (iAll > 3) 
	{
		if (i > 0) 	{
			if (iAll - 1 - aTumbnails[2] < 2){ 
				oRight.className = sInvisibleClassName;
			}
		}    
		else if (i < 0) 
		{
			if (aTumbnails[0] < 2) 	{
				oLeft.className = sInvisibleClassName;
			}
		}
		else if (i == 0) {
			oLeft.className = sInvisibleClassName;
		}
	} else {
		oLeft.className = sInvisibleClassName;
		oRight.className = sInvisibleClassName;        	
	}
}
function _updateLeftRight() 
{
	oLeft.className = '';
	oRight.className = '';
	if (iAll > 3) {
		if (iAll - 1 - iCurrent < 1 || aTumbnails[2] == iAll-1) {
			oRight.className = sInvisibleClassName;
		}
		if (iCurrent < 1 || aTumbnails[0] == 0) {
			oLeft.className = sInvisibleClassName;
		}
	} else {
		oLeft.className = sInvisibleClassName;
		oRight.className = sInvisibleClassName;      
	}
}
    
function _getPicByIndex(i)  
{
	var pic = document.getElementById("pic_" + i);
	//if (!pic) throw new Error('Zdjecie o numerze ' + i + ' nie istnieje');
	return pic;
}

function _scroll(i)
{
	_updateLeftRight2(i);
	aTumbnails = [aTumbnails[0]+i, aTumbnails[1]+i, aTumbnails[2]+i];
	_pokazMiniaturki();
}

function _updateThumbnailArr() 
{
	var bTmp = false;
	
	for (var i=0; i<aTumbnails.length; i++) {
		if (aTumbnails[i] == iCurrent) {
			bTmp = true; 
			break;
		}
	}
	if (bTmp == false) {
		if (aTumbnails[2] < iCurrent) {
			aTumbnails = [iCurrent-2, iCurrent-1, iCurrent];
		} else {
			aTumbnails = [iCurrent, iCurrent+1, iCurrent+2];
		}
	}    	
}

function _pokazMiniaturki()
{
	
	for (var i=0; i<aPics.length; i++) 	{
		this.aPics[i].className = sTumbnailHiddenCN;
	}    
	for (var i=0; i<aTumbnails.length; i++) {
		this.aPics[aTumbnails[i]].className = ''; 
	}  
}