[Javascript] Hide show a TD

[Marcelo Wolfgang]

Hi list,

I'm trying to come with a script to hide show layers based on their
id, everything looks fine, except it ain't changing the style of the
TD :(

Here's my js code :

<script>
function showSub(id){
       alert( document.getElementById(id).style.display) // output "none"
       document.getElementById(id).style.display == 'inline';
       alert( document.getElementById(id).style.display) // output
"none" also !!!

      // I do not even tried to debug the rest of the function
      // but I bet it won't change the dislplay attribute also.

       for (i=1;i<5; i++){
               if (i!= id){
                       document.getElementById(i).style.display == 'none';
               }
       }
}
</script>

and here's the TD :

<tr>
       <td><a href="javascript:showSub(1)"><img
src="images/menu_btProducts_off.gif" width="134" height="23"
border="0"></a></td>
</tr>
<tr>
       <td id="1" style="display:none">
               <table border="0" cellpadding="0" cellspacing="0">
               <tr>
                       <td><img src="images/menu_btShopMedia_off.gif"
width="134"
height="22" border="0"></td>
               </tr>
               <tr>
                       <td bgcolor="#20214F"><img src="images/dot.gif" width="1"
height="1" border="0"></td>
               </tr>
               </table>
       </td>
</tr>

Can anyone help me ?

TIA
Grillo