function showBox(event,id) {
  document.getElementById('art' + id).style.opacity = '0';
  document.getElementById('art' + id).style.filter = 'alpha(opacity=0)';
  document.getElementById('art' + id).style.display = 'block';
  document.getElementById('art' + id).style.top = (document.all) ? window.event.y + document.body.scrollTop : (event.pageY - 20) + 'px';
  document.getElementById('art' + id).style.left = (document.all) ? window.event.x + document.body.scrollLeft : (event.pageX + 10) + 'px';

  var steps=10;
  var duration=250;
  for (var i=0; i<=steps; i++) {
    var func="";
    if (navigator.appVersion.indexOf("MSIE")>=0) { // IE
      func+="document.getElementById('art' + "+id+").style.filter=\"alpha(opacity="+((i/steps)*100)+")\";\n";
    } else {
      func+="document.getElementById('art' + "+id+").style.opacity="+(i/steps)+";\n";
    }
    setTimeout(func, 1+Math.floor(i*duration/steps));
  }

}

function hideBox(event,id) {
  document.getElementById('art' + id).style.display = 'none';
}