[jQuery] problem with closing all found divs

Hi,

my source looks like this:

<table width="100%" border="0" id="edit_categories">
<tr>
<td colspan="3" align="right"><a href="/admin/index.php?
action=categories&function=add&sub=add">Neu hinzufügen</a> <br /> <br /
></td>
</tr>
<tr style="background-color: #EEEEFF;">
<td>
<span class="name_1" style="font-weight:bold">Packstoff und
Packmittel aus Aluminium</span>
<div class="edit_box_1">
<input type="text" name="new" id="feld_1" size="50"
class="editfield" />
<div></div>
<input type="button" name="savebutton" id="button_1" value="Änderung
speichern" />
</div>
</td>
<td align="center"><a href="/admin/index.php?
action=categories&function=delete&prg_id=1" onClick="return confirm
('Wirklich löschen?')"><img src="../img/delete.png" alt="" width="16"
height="16" border="0" /></a></td>
<td align="center"><a href="#"><img class="open_edit_box" id="1"
src="../img/edit.png" alt="" width="16" height="16" border="0" /></a></
td>
</tr>

<tr style="background-color: #FFFFFF;">
<td>
|&nbsp;--&nbsp;<span class="name_96" >Aluminium - Siegelrandschalen</
span>
<div class="edit_box_96">
<input type="text" name="new" id="feld_96" size="50"
class="editfield" />
<div></div>
<input type="button" name="savebutton" id="button_96" value="Änderung
speichern" />
</div>
</td>
<td align="center"><a href="/admin/index.php?
action=categories&function=delete&prg_id=96" onClick="return confirm
('Wirklich löschen?')"><img src="../img/delete.png" alt="" width="16"
height="16" border="0" /></a></td>
<td align="center"><a href="#"><img class="open_edit_box" id="96"
src="../img/edit.png" alt="" width="16" height="16" border="0" /></a></
td>
</tr>
......

My jquery:

if ( $("#edit_categories").length > 0 ) {
// close all by default
$('.edit_categories>tr>td>div').hide();
$('.open_edit_box').click(function(){
var prg_id = this.id;
// close all
$('.edit_categories>tr>td>div').hide();
// open requested one
$('.edit_box_'+prg_id).show();
});

}

For some reason, the first table row stays always open... the second
(and all following) are closed.
What I do wrong? Is there a better way? I decided for this way, as I
don't Know the div names, as they get filled by database id's.

Thanks for help!

Heidi