function showImg(url,width,height) {
       day = new Date();
       id = day.getTime();
       eval("page" + id + " = window.open(url, '" + id + "', 'toolbar=0,scrollbars=0,location=0,statusbar=0,menubar=0,resizable=0,width="+width+",height="+height+",left = "+((screen.width - width) /2) +",top = "+((screen.height - height) /2)+"');");
       }   
           
       function changeImg(img,src) {
           
           img.style.backgroundImage = "url('"+src+"')";
           
       }