How to overlay a div (or any element) over a table row (tr)?

I'd like to overlay a div (or any element that'll work) over a table row (tr tag) that happens to have more than one column.

I have tried a few methods, which don't seem to work. I've posted my current code below.

I do get an overlay, but not directly over just the row. I tried setting the overlay top to $divBottom.css('top'), but that is always 'auto'.

So, am I on the right track, or is there a better way of doing it? Utilizing jQuery is fine as you can see.

If I am on the right track, how do I get the div placed correctly? Is the offsetTop an offset in the containing element, the table, and I need to do some math? Any other gotchas I'll run into with that?

$(document).ready(function() {
  $('#lnkDoIt').click(function() {
    var $divBottom = $('#rowBottom');
    var $divOverlay = $('#divOverlay');
    var bottomTop = $divBottom.attr('offsetTop');
    var bottomLeft = $divBottom.attr('offsetLeft');
    var bottomWidth = $divBottom.css('width');
    var bottomHeight = $divBottom.css('height');
    $divOverlay.css('top', bottomTop);
    $divOverlay.css('left', bottomLeft);
    $divOverlay.css('width', bottomWidth);
    $divOverlay.css('height', bottomHeight);

    $('#info').text('Top: ' + bottomTop + ' Left: ' + bottomLeft);
  });
});

#rowBottom { outline:red solid 2px }
#divBottom { margin:1em; font-size:xx-large; position:relative; }
#divOverlay { background-color:Silver; text-align:center;  position:absolute; z-index:10000; opacity:0.5; }

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<html>
  <head>
    <title>Overlay Tests</title>
  </head>
  <body>
    <p align="center"><a id="lnkDoIt" href="#">Do it!</a></p>
    <table width="100%" border="0" cellpadding="10" cellspacing="3" style="position:relative">
      <tr>
        <td><p>Lorem ipsum dolor sit amet, consectetur adipiscing elit.</p></td>
      </tr>
      <tr id="rowBottom">
        <td><div id="divBottom"><p align="center">This is the bottom text</p></div></td>
      </tr>
      <tr>
        <td><p>Lorem ipsum dolor sit amet, consectetur adipiscing elit.</p></td>
      </tr>
    </table>
    <div id="divOverlay" style=""><p>This is the overlay div.</p><p id="info"></p></div>
  </body>
</html>

You need to make the overlay div have an absolute position. Also use the position() jQuery method for top and left positions of the row - here are the missing pieces:

var rowPos = $divBottom.position();
bottomTop = rowPos.top;
bottomLeft = rowPos.left;

//
$divOverlay.css({
    position: 'absolute',
    top: bottomTop,
    left: bottomLeft,
    width: bottomWidth,
    height: bottomHeight
});

Make:

div style="position:absolute"

td style="position:relative;display:block"

and you don't need jquery.

<!--only this the structure you need to make it visible-->


<!-- this is a wrapper -->
<div style="position: relative;"> 
   
    <div style="position: absolute;"> i'm on the top</div> <!-- here the things you want on top -->

 <!-- everything code you want to write -->
    <table></table>
</div>

How to overlay a div (or any element) over a table row (tr)?

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