function popup(url) {
//zmiana wielkosci popupa
	newwindow=window.open(url,'name','height=800,width=880');
	if (window.focus) {newwindow.focus()}
	return false;
}

function paintBorder() {

	var thumbs = document.getElementById('thumbs');
	var thumbs2 = document.getElementById('thumbs2');

	for(i = 0; i < thumbs.childNodes.length; ++i) {
	
		thumbs.childNodes[i].style.border = "1px solid white";
	
	}
	
	for(i = 0; i < thumbs2.childNodes.length; ++i) {
	
		thumbs2.childNodes[i].style.border = "1px solid white";
	
	}

	if(currentImage <= 3) {
	
		thumbs.childNodes[currentImage].style.border = "1px solid black";
	
	} else {
	
		thumbs2.childNodes[currentImage - 4].style.border = "1px solid black";
	
	}

}

function next() {

	++currentImage;
	
	if(currentImage >= images.length) {
	
		currentImage = 0;
	
	}
	
	displayImage(currentImage);

}

function prev() {

	--currentImage;
	
	if(currentImage < 0) {
	
		currentImage = images.length - 1;
	
	}
	
	displayImage(currentImage);

}

function displayImage(i) {

	currentImage = i;
	
	mainImage.innerHTML = "<img src='" + images[i] + "' />";
	
	paintBorder();

}