var mouseX;
var mouseY;

document.onmousemove = getMouseCoordinates;

function getMouseCoordinates ( event ) {
  ev = event || window.event;
  
  if ( document.all ) {
    mouseX = ev.clientX + document.body.scrollLeft;
    mouseY = ev.clientY + document.body.scrollTop;
  } else {
    mouseX = ev.pageX;
    mouseY = ev.pageY;
  }
}

function showPics ( foto ) {  // visualizza la miniatura
  document.getElementById(foto).style.left = mouseX + 15 + "px";
  document.getElementById(foto).style.top = mouseY + 20 + "px";
  document.getElementById(foto).style.visibility = "visible";
}

function showSlide ( foto ) {  // visualizza la miniatura
  document.getElementById(foto).style.visibility = "visible";
}

function hidePics ( foto ) {  // nasconde la miniatura
  document.getElementById(foto).style.visibility = "hidden";
}