var loading = new Image(190,30);
loading.src = "http://www.bazeny-zumpy.cz/public/images/loader.gif";
var imgUrl;

function changeImg(url){
    var img = new Image();
    img.onload=new Function("isLoaded();");
    document.getElementById("loading").style.visibility = "visible";
    img.src = "http://www.bazeny-zumpy.cz/public/images/fotky/" + url;
    imgUrl = url;
}

function isLoaded(){
		document.getElementById("large_img").src = "http://www.bazeny-zumpy.cz/public/images/fotky/" + imgUrl;
        document.getElementById("loading").style.visibility = "hidden";
}