var navigation_imagesArray = new Array(); // arrays of strings of the src of the navigation_images
var navigation_imagesOnArray = new Array();
var navigation_imagesOff; // array of img element directly copied from the page
var navigation_imagesOn; // array of img element dynamically pre-loaded
var navigation_images;  // container holding the page's navigation elements

/* new functions  (mootools dependancy)*/
function Navigation_Initialize() {
    
    navigation_images = $$('.navigation_preload a img');
    for (var i = 0; i < navigation_images.length; i++) {
        // /pathtoimage/imagename.ext
        var src = navigation_images[i].get('src');
        // create a /pathtoimage/imagename_on.ext string:
        var srcOn = src.substring(0, src.length - 4) + '_on' + src.substring(src.length - 4,src.length);
       
        //copy values to image name array:
        navigation_imagesArray.push(navigation_images[i].get('src'));
        navigation_imagesOnArray.push(srcOn);


        navigation_images[i].set('photoindex', i);
    }

    navigation_imagesOff = new Asset.images(navigation_imagesArray, {
        onComplete: function() {
            Navigation_LoadOnImages();
        }
    });
}

function Navigation_LoadOnImages() {
    
    navigation_imagesOn = new Asset.images(navigation_imagesOnArray);
    Navigation_WireUpHovers();
    
}

function Navigation_WireUpHovers() {

    for (var i = 0; i < navigation_images.length; i++) {

        var parent = navigation_images[i].getParent();

        if (parent.href == document.location.href) {
            navigation_images[i].src = navigation_imagesOn[navigation_images[i].get('photoindex')].src;
        }
        else {
            $(navigation_images[i]).addEvent('mouseover', function() {

                this.src = navigation_imagesOn[this.get('photoindex')].src;
            });

            $(navigation_images[i]).addEvent('mouseleave', function() {
                this.src = navigation_imagesOff[this.get('photoindex')].src;
            });
        }
    }
}

window.addEvent('domready', function() {
    Navigation_Initialize();
});


function Over(currobj, targetLink) {
    
    currobj.className += " over";
    mag.gid(targetLink).src = "/images/" + targetLink + "_on.jpg";
}
function Out(currobj, targetLink) {
    currobj.className = currobj.className.replace("over", "");
    mag.gid(targetLink).src = "/images/" + targetLink + ".jpg";
}