style.left i NS6.1

Hvordan får jeg style.left som i eks. nedenunder til at virke på et objekt i Netscape 6.1.

<html>
<head>
    <title>NS6</title>
</head>
<body>

<script language="JavaScript" type="text/javascript">
  function tableRight(){
    var table = document.getElementById("tabletest");
    x = table.offsetLeft;
    table.style.left = x + 100;
  }
 
  function tableLeft(){
    var table = document.getElementById("tabletest");
    x = table.offsetLeft;
    table.style.left = x - 100;
  }
</script>

<table id="tabletest" border="1" style="position: absolute; left: 0px; top: 0px;">
<tr><td>1</td><td>2</td></tr>
</table>
<br><br>
<input type="button" onClick="tableLeft()" value="Move Left">
<input type="button" onClick="tableRight()" value="Move Right">
</body>
</html>