Show/hide layer Help!!!!

[phoenix211984]

I have a PHP web page designed in dreamweaver mx 2004 that has 5 dependant dropdown menus.(from mx widgets extension) that get data from a mysql database.

The dependant dropdowns are:
Make
Model
Spec
Job
Area

The job section has a list of Clutch, brakes, full service and so on. Upon selecting Brakes from the JOB menu i have a hidden layer multiple selection field that should show with four options that the user can choose from such as (Rear Brakes, Front Brakes and so on)

My problem is that i want the multiple selection field hidden unless the user selects BRAKES from the JOB dropdown. At the moment it is showing when any job is chosen.

I would be grateful for any help. Thanks in advance.

Code i am using

<td height="33">Job:</td>
<td><select name="job" id="job" onChange="MM_showHideLayers('Layer1','','show')">
<option value="value"><--Please Select---></option>
<?php
do {
?>
<option value="<?php echo $row_rsJobs['job_id']?>"><?php echo $row_rsJobs['job_name']?></option>
<?php
} while ($row_rsJobs = mysql_fetch_assoc($rsJobs));
$rows = mysql_num_rows($rsJobs);
if($rows > 0) {
mysql_data_seek($rsJobs, 0);
$row_rsJobs = mysql_fetch_assoc($rsJobs);
}
?>
</select></td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<td><div id="Layer1" style="position:absolute; width:200px; height:28px; z-index:1; left: 312px; top: 170px; visibility: hidden;">
<select name="select" size="4" multiple>
<option value="1" selected>Front Brake Discs</option>
<option value="2">Rear Brake Discs</option>
<option value="3">Front Brake Pads</option>
<option value="4">Rear Brake Pads</option>
</select>
</div></td>