var last;

function show(event, id) {
  if (last) {
    hide(event, last);
  }
  var mousex = event.pageX; //+document.body.scrollLeft;
  var mousey = event.pageY; //y+document.body.scrollTop;
  if (!mousex) {
   mousex = event.x + document.body.scrollLeft;
   mousey = event.y + document.body.scrollTop;
  }
  elt = document.getElementById(id);
  elt.style.top = (mousey - 50) + 'px';
  elt.style.left = (mousex + 50) + 'px';
  elt.style.visibility = 'visible';
  elt.style.width = '250px';
//  elt.style.display = 'block';
//  alert(mousex + "," + mousey);

  last = id;
}

function hide(evt, id) {
  elt = document.getElementById(id);
  elt.style.visibility = 'hidden';
//  elt.style.display = 'none';
}