js求助－表格由下到上的渐显

<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312">
<title>表格渐显</title>
<style type="text/css">
<!--
.page_table {
filter: Alpha(Opacity=100, FinishOpacity=0, Style=1, StartX=0, StartY=0, FinishX=0, FinishY=140);
}
-->
</style>
</head>
<body>
<table id="tabbb" style="visibility:hidden;width:285;height:140;" border="0"  cellspacing="0" cellpadding="0" bgcolor="#FF0000" class="page_table" >
<tr>
<td>　</td>
</tr>
</table>
</body>
</html>
<script language="javascript">
<!--
function gon2(){
var showInterval = 2; 
objx = document.getElementById("tabbb");
objx.style.clip = "rect("+T+"px 285px "+originalT+"px 0px)";
if(T>=0)
{
T-= 5;
setTimeout("gon2()", showInterval);
}
}
//-->
</script>
<script language="javascript">
<!--
var originalT;
var T;
originalT = document.getElementById("tabbb").offsetHeight;
T = originalT - 1;
document.getElementById("tabbb").style.visibility = 'visible';
gon2();
//-->
</script>