function changeImage(filename)
{
  document.mainimage.src = filename;
}

function OpenPopup (c) {
window.open(c,
'window',
'width=650,height=600,scrollbars=yes,status=yes');
}

function playSound(soundfile) {
 document.getElementById("dummy").innerHTML="<embed src=\""+soundfile+"\" hidden=\"true\" autostart=\"true\" loop=\"false\" width=\"0\" height=\"0\" />";
 }