I'd like to add a lightbox effect to the Pop Up

I have PopUp installed but don’t know what it does not show up…

I’d like to add a lightbox effect to the pop up that happens here:

http://lamsocialclub.com/

As you can see from the screenshot, not a good visual without making the outer box opacity 80% with black.

I tried adding this:

<div id="cboxOverlay" style="display: block; opacity: 0.9; cursor: pointer;"></div>

above the rest:`

<div id='<?php echo $popover_messagebox; ?>’ class=’visiblebox’ style='<?php echo $style; ?>’>

<a href=” id=’closebox’ title=’Close this box’></a>

<div id=’message’ style='<?php echo $box; ?>’>

<?php echo do_shortcode($popover_content); ?>

<div class=’clear’></div>

<?php if($popover_hideforever != ‘yes’:wink: {

?>

<div class=’claimbutton hide’><a href=’#’ id=’clearforever’><?php _e(‘Never see this message again.’,’popover’:wink:; ?></a></div>

<?php

}

?>

</div>

<div class=’clear’></div>

</div>`

But when I close the box the black does not go away.

Please advice.

Thank you,

Giovanni