function moveTractor(event)
{
  var event = event || window.event || null;
  var tractor = document.getElementById("tractor");
  tractor.style.left = event.clientX + 20;
  tractor.style.top = event.clientY + 20;
}

document.onmousemove = moveTractor;

var smokeShift = 10;

function animateSmoke()
{
  var tractor = document.getElementById("tractor");
  var smoke = document.getElementById("smoke");
  smoke.style.left = parseInt(tractor.style.left.replace("px", "")) + smokeShift;
  smoke.style.top = parseInt(tractor.style.top.replace("px", "")) - (smokeShift * 2);
  if (smokeShift < 20) smokeShift++; else smokeShift = 10;
}

function setTimers()
{
  setInterval("animateSmoke()", 200);
}

function showHint(text)
{
  var hint = document.getElementById("hint");
  hint.innerHTML = "<br/><i>" + text + "</i>";
  hint.style.visibility = "visible";
  return true;
}

function hideHint()
{
  var hint = document.getElementById("hint");
  hint.style.visibility = "hidden";
  return true;
}