function ShowPopup(hoveritem)
{
  hp = document.getElementById("hoverpopup");

  // Set position of hover-over popup
  hp.style.top = hoveritem.offsetTop + 50;
  hp.style.left = hoveritem.offsetLeft + 40;
 
  // Set popup to visible
  hp.style.visibility = "Visible";
}

function HidePopup()
{
  hp = document.getElementById("hoverpopup");
  hp.style.visibility = "Hidden";
}