why does text show through layer?

[shiningpixel]

I'm using Dreamweaver to create layers that show/hide on a mouseover.

The first (2) layers in the sequence seem to have transparent backgrounds, and the text below shows through. I want layers to be opaque.

Any clues?

I've pasted in the table code...
************************************************** *****

<table width="100%" border="0" cellpadding="0" cellspacing="0">
              <tr align="left" valign="top">
                <td width="17">&nbsp;</td>
                <td width="5">&nbsp;</td>
                <td width="17"><img src="images/dotgrn.gif" width="17" height="18"></td>
                <td width="370" class="bodyText" style="position: relative;"><span class="bodyTextBold"><a class="large" href="#" onMouseOver="MM_showHideLayers('inhalation','','show')" onMouseOut="MM_showHideLayers('inhalation','','hide')">Inhalation</a></span><br>
  The lungs are designed to absorb dissolved gasses and and
  vapors and put them directly into the blood stream.                    
<div id="inhalation" style="position:absolute; left:0px; top:15px; width:500px; height:100px; z-index:4; background-color: #FFFFFF; layer-background-color: #FFFFFF; border: 1px solid #003300; visibility: hidden;">
<table width="100%" border="0" cellspacing="0" cellpadding="5">
<tr>
<td class="bodyTextBoldRed">&nbsp;</td>
<td>&nbsp;</td>
<td rowspan="3"><img src="images/lungs.jpg" width="78" height="90"></td>
</tr>
<tr>
<td rowspan="2" class="bodyText">Work with volatile chemicals in a chemical fume hood </td>
<td>&nbsp;</td>
</tr>
<tr>
<td>&nbsp;</td>
</tr>
</table>
</div></td>
<td class="bodyText"><img src="images/lungs.jpg" width="58" height="66"></td>
              </tr>
              <tr align="left" valign="top">
                <td><img src="images/percutaneous.jpg" width="99" height="65"></td>
                <td width="5">&nbsp;</td>
                <td><img src="images/dotgrn.gif" width="17" height="18"></td>
                <td width="370" class="bodyText" style="position: relative;"><span class="bodyTextBold"><a class="large" href="#" onMouseOver="MM_showHideLayers('injection','','show')" onMouseOut="MM_showHideLayers('injection','','hide')">Injection or
 break in the skin</a></span><br>
Hazardous agents can be introduced into the body via needle sticks, glass shards,
razor blades.
<div id="injection" style="position:absolute; left:0px; top:15px; width:500px; height:100px; background-color: #FFFFFF; layer-background-color: #FFFFFF; border: 1px solid #003300; visibility: hidden; z-index: 3;">
  <table width="100%" border="0" cellspacing="0" cellpadding="5">
    <tr>
      <td class="bodyTextBoldRed">&nbsp;</td>
      <td>&nbsp;</td>
      <td rowspan="3"><img src="images/percutaneous.jpg" width="135" height="90"></td>
    </tr>
    <tr>
      <td rowspan="2" class="bodyText">Use needles with built in safety devices,
        avoid using razor blades</td>
      <td>&nbsp;</td>
    </tr>
    <tr>
      <td>&nbsp;</td>
    </tr>
  </table>
</div></td>
                <td class="bodyText">&nbsp;</td>
              </tr>
              <tr align="left" valign="top">
                <td>&nbsp;</td>
                <td width="5">&nbsp;</td>
                <td><img src="images/dotgrn.gif" width="17" height="18"></td>
                <td width="370" class="bodyText" style="position: relative;"><span class="bodyTextBold"><a class="large" href="#" onMouseOver="MM_showHideLayers('skin','','show')" onMouseOut="MM_showHideLayers('skin','','hide')">Skin absorption</a></span><br>
Certain chemicals can penetrate the skin, often due to a local anesthetic effect
  without user knowledge.
  <div id="skin" style="position:absolute; left:0px; top:15px; width:500px; height:100px; background-color: #FFFFFF; layer-background-color: #FFFFFF; border: 1px solid #003300; visibility: hidden; z-index: 4;">
    <table width="100%" border="0" cellspacing="0" cellpadding="5">
      <tr>
        <td class="bodyTextBoldRed">&nbsp;</td>
        <td>&nbsp;</td>
        <td rowspan="3"><img src="images/absorption.jpg" width="138" height="90"></td>
      </tr>
      <tr>
        <td rowspan="2" class="bodyText">Wear appropriate PPE including lab coat,
          gloves and closed toed shoes</td>
        <td>&nbsp;</td>
      </tr>
      <tr>
        <td>&nbsp;</td>
      </tr>
    </table>
  </div></td>
                <td class="bodyText"><img src="images/absorption.jpg" width="101" height="65"></td>
              </tr>
   </table>

Edited: Cleaned up code for readability - Brak

[pyrodragon]

replace layer-background-color with background and this should fix the problum