var id,
    stepX, stepY;
    function Start()
{
       document.all.Logo.style.pixelLeft =
        document.body.offsetWidth / 2;
    document.all.Logo.style.pixelTop =
        document.body.offsetHeight / 20;
    document.all.Logo.style.visibility = "visible";
    stepX = (Math.random()+1)  * 1;
    stepY = (Math.random()+1)  * 1;
    id = window.setInterval("Move()",40);
}
  function Stop()
{
        window.clearInterval(id);
       document.all.Logo.style.visibility = "hidden";
}
  function Move()
{
        document.all.Logo.style.pixelLeft += stepX;
    document.all.Logo.style.pixelTop += stepY;
        if (document.all.Logo.style.pixelLeft <= 0) stepX = -stepX;
      if ( document.all.Logo.style.pixelLeft >=
         (document.body.offsetWidth - document.all.Logo.width
          - stepX - 22) ) stepX = -stepX;
            if (document.all.Logo.style.pixelTop <= 0) stepY = -stepY;
        if ( document.all.Logo.style.pixelTop >=
         (document.body.offsetHeight - document.all.Logo.height
          - stepY) ) stepY = -stepY;
}