How do you do selected in a multi-value list box in a form?

[rich]

I am populating a list box from a dictionary table and then picking
muliple values to insert into a detail table. How do I get the list box
to have multiple selections highlighted when I pick one of the master
items?

[rich]

Here is part of the code with explaination

This is the cell in a table that is part of a form.

<td>
<select name="stages[]" multiple="multi ple">
<?php
$allstages = allstages();
while ($allstagerows= pg_fetch_array( $allstages)) {
$eachstage= $allstagerows["stageid"];
while($drcatrow = pg_fetch_array( $dresscat)){
if ($drcatrow["stageid"] == $eachstage){ ?>
<option value=<?php echo $eachstage;?> selected="selec ted"><?php
echo $allstagerows["stage"]?></option>
<?php }else{ ?>
<option value=<?php echo $eachstage;?>>< ?php echo
$allstagerows["stage"]?></option>
<?php }
}
}
?>
</select>
</td>

[rich]

Here is the form I designed.
This form is to take a dressing type and choose all the wound stages it
can be used on.
there are 3 tables

dressing type table
dresstypeid
dressingtype

stages table
stageid
stage

dressingcat table
dresstypeid
stageid

<form name="dresstype form" method="post" action="<?php print
$_SERVER['PHP_SELF']?>">
<?php
$dresstypeid = $_REQUEST['dresstypeid'];
if ($dresstypeid >0) {
$drtresult = specificdressty pe($dresstypeid ); // query for the
specific dressing type
$dresscat = specdresscat($d resstypeid); //query for the wound stages
for a dressing type
$drtyperow = pg_fetch_array( $drtresult);
?>
<input type=hidden name="dresstype id" value= "<?php echo
$drtyperow["dresstypei d"]?>">
<?php
}
?>
<input type=hidden name="dresstype id" value= "<?php echo
$drtyperow["dresstypei d"]?>">
<fieldset>
<legend>Dressin g Type Information</legend>
<table align="left">
<tr>
<td><label for "dresstype">Dre ssing type</label></td>
</tr>
<tr>
<td><input type=text size="50" name=dresstype value = "<?php echo
$drtyperow["dressingty pe"]?>" ></td>
</tr>
<tr>
<td><label for "stages">Stages </label></td>
</tr>
<tr>
<td>
<select name="stages[]" multiple="multi ple">
<?php
$allstages = allstages(); //query to populate the listbox with all the
stages in the stage table
while ($allstagerows= pg_fetch_array( $allstages)) {
$eachstage= $allstagerows["stageid"];
while($drcatrow = pg_fetch_array( $dresscat)){
if ($drcatrow["stageid"] == $eachstage){ ?>
<option value=<?php echo $eachstage;?> selected="selec ted"><?php echo
$allstagerows["stage"]?></option>
<?php }else{ ?>
<option value=<?php echo $eachstage;?>>< ?php echo
$allstagerows["stage"]?></option>
<?php }
}
}
?>
</select>
</td>
</tr>
</table>
</fieldset>
<table align="left">
<tr>
<td><input type="submit" name="upddresst ype" value="Add-Update Dressing
Type" ></td>
</tr>
</table>

</form>