function opacity(id, opacStart, opacEnd, millisec) {
  if (document.getElementById(id)) {
    var speed = Math.round(millisec / 100);
    var timer = 0;
    if (opacStart > opacEnd) {
      for (i = opacStart; i >= opacEnd; i--) {
        setTimeout("changeOpac(" + i + ",'" + id + "')",(timer * speed));
        timer++;
      }
    } else if (opacStart < opacEnd) {
      for (i = opacStart; i <= opacEnd; i++) {
        setTimeout("changeOpac(" + i + ",'" + id + "')",(timer * speed));
        timer++;
      }
    }
  }
}
function changeOpac(opacity, id) {
  var object = document.getElementById(id).style;
  object.opacity = (opacity / 100);
  object.MozOpacity = (opacity / 100);
  object.KhtmlOpacity = (opacity / 100);
  object.filter = "alpha(opacity=" + opacity + ")";
    document.getElementById(id).style.visibility = "visible";
}