Hvorfor virker onmouseover/out ikke

Jeg bruger nedenstående script.

Hvorfor virker onmouseover og onmouseout ikke når man bruger dette script ????


<HEAD>

<style type="text/css">
#minDiv {
  visibility: visible;
  position: relative;
  width: 100%;
  height: 100%;
  filter: alpha(opacity=100);
  -moz-opacity: 0;
}
</style>
<script type="text/javascript">
akt = null;

var i, l;

function visTxt(nr) {
  if (akt != nr) {
    akt = nr;
    t = document.getElementById("minDiv");
    t.style.visibility = "hidden";
    t.innerHTML = document.getElementById("txt" + nr).innerHTML;
    t.style.left = -20;
    if (document.all)
      t.filters.opacity = 0;
    else
      t.style.MozOpacity = 0;
    i = 0;
    l = -20;
    t.style.visibility = "visible";
    loopTxt();
  }
}

function loopTxt() {
  ++i;
  t = document.getElementById("minDiv");
  l += Math.ceil((0 - l) * 0.25);
  if (l > 0)
    l = 0;
  t.style.left = l;
  if (document.all)
    t.filters.alpha.opacity = i * 20;
  else
    t.style.MozOpacity = (i * 20) / 100;
  if (i < 20)
    setTimeout("loopTxt();", 50);
}
</script>
</HEAD>

<BODY onload="visTxt(1); return false;">
<div id="minDiv"></div>
<div id="txt1" style="display: none;">
<TABLE>
<TR>
<td onMouseOver="download.src=&quot;download2.gif&quot;" onMouseOut="download.src=&quot;download.gif&quot;" style="cursor: hand;"><img name="download" src="download.gif" border="0" width="15" height="19" align="bottom" alt=""></td>
</TR>
</TABLE>
</BODY>