addLoadEvent(Catalogue);

function Catalogue() {
    var imagesUrl = Array();
    var ul = null;
    var current = 0;
    var photo = document.getElementById('currentCatalog').getElementsByTagName('img')[0];
    var link = document.getElementById('currentCatalog').getElementsByTagName('a')[0];
    
    ul = document.getElementById('promotionCatalogue');
    if (ul) {
        var as = ul.getElementsByTagName('a');
        for (var i = 0; i < as.length; i++) {
            if (as[i].className.indexOf("photopopup") != -1) {
                imagesUrl.push(as[i].href);
            }
        }
        
        var prev = document.getElementById('prevCatalog');
        var next = document.getElementById('nextCatalog');

        next.onfocus = function() {
            this.blur();
        }
        next.onclick = function() {
            if ( (current + 1) < imagesUrl.length) { 
                current++;
                checkVis();
                setPhoto();
            }
            return false;
        }
        
        prev.onfocus = function() {
            this.blur();
        }
        prev.onclick = function() {
            if (current > 0) {
                current--;
                checkVis();
                setPhoto();
            }
            return false;
        }
                
        function setPhoto() {
            var loader = document.createElement('img');
            loader.setAttribute('id', 'catalogueLoader');
            loader.setAttribute('src', 'images/catalogueLoader.gif');
            loader.setAttribute('alt', ''); 
            ul.appendChild(loader);
            var imagePreload = new Image();	
            imagePreload.onload = function() {
                link.href = imagePreload.src;
                photo.src = imagePreload.src.replace("ofertySpecjalne/","ofertySpecjalne/md/");
                ul.removeChild(loader);
                return true;
            }
            imagePreload.src = imagesUrl[current];
            return true;
        }
        
        function checkVis() {
            var prevStyle = prev.getElementsByTagName('a')[0];
            var nextStyle = next.getElementsByTagName('a')[0];
            if (current == 0) {
               prevStyle.style.display = 'none';
            } else {
               prevStyle.style.display = 'block';
            }
            if ((current+1) == imagesUrl.length) {
               nextStyle.style.display = 'none'; 
            } else {
               nextStyle.style.display = 'block';
            }
            return true;
        }
        
        checkVis();
        
    }
    
    
    
    
    
}