Edit in JSFiddle

<!-- Start Dialog Box -->
<div id="kotak-dialog">
<h3 class="title">Sukai Halaman<a href="#" class="close">&times;</a></h3>
     <div id="iframeContainer"><figure class="fb-like-box fb_iframe_widget" data-colorscheme="light" data-header="false" data-href="https://www.facebook.com/Infok.moe" data-show-border="false" data-show-faces="true" data-stream="false" fb-xfbml-state="rendered" fb-iframe-plugin-query="app_id=390824627655103&amp;color_scheme=dark&amp;header=false&amp;href=https%3A%2F%2Fwww.facebook.com%2FInfok.moe&amp;locale=id_ID&amp;sdk=joey&amp;show_border=false&amp;show_faces=true&amp;stream=false"><span style="vertical-align: bottom; width: 300px; height: 241px;"><iframe name="f1d3db2c5" width="1000px" height="1000px" frameborder="0" allowtransparency="true" scrolling="no" title="fb:like_box Facebook Social Plugin" src="http://www.facebook.com/v2.0/plugins/like_box.php?app_id=390824627655103&amp;channel=http%3A%2F%2Fstatic.ak.facebook.com%2Fconnect%2Fxd_arbiter%2FZEbdHPQfV3x.js%3Fversion%3D41%23cb%3Df18f21635%26domain%3Dwww.infokmu.com%26origin%3Dhttp%253A%252F%252Fwww.infokmu.com%252Ff21f572008%26relation%3Dparent.parent&amp;color_scheme=dark&amp;header=false&amp;href=https%3A%2F%2Fwww.facebook.com%2FInfok.moe&amp;locale=id_ID&amp;sdk=joey&amp;show_border=false&amp;show_faces=true&amp;stream=false" style="border: none; visibility: visible; width: 300px; height: 241px;" class=""></iframe></span></figure></div>
</div>
<div id="dialog-overlay"></div>
<!-- End Dialog Box -->

var $dialog = $('#kotak-dialog'),
    $overlay = $('#dialog-overlay'),
    $frame = $('#iframeContainer');

// Check
if (!readCookie('fb_box_once')) {
    $(window).load(function() {
        $dialog.show();
        $overlay.fadeTo(400, 0.8);
        return false;
    });
}

$dialog.find('.close').click(function() {
    // Set
    createCookie('fb_box_once', null, 9999);
    $dialog.fadeOut('normal', function() {
        $frame.remove();
    });
    $overlay.hide();
    return false;
});

/* Visit: http://hompimpaalaihumgambreng.blogspot.com */

body {
  padding:100px;
  font:normal 11px Arial,Sans-Serif;
}

#kotak-dialog {
  position:absolute;
  top:20%;
  left:50%;
  margin:0px 0px 0px -200px;
  max-width:400px;
  height:auto;
  background-color:#fff;
  -webkit-box-shadow:0px 1px 2px rgba(0,0,0,0.4);
  -moz-box-shadow:0px 1px 2px rgba(0,0,0,0.4);
  box-shadow:0px 1px 2px rgba(0,0,0,0.4);
  z-index:1000;
  display:none;
}

#kotak-dialog *:focus {
  outline:none;
}

#kotak-dialog h3.title {
  background-color:#3B5998;
  padding:10px 15px;
  color:#fff;
  font:normal 16px Arial,Sans-Serif;
  margin:0px 0px 0px 0px;
  position:relative;
}

#kotak-dialog h3.title a {
  position:absolute;
  top:10px;
  right:15px;
  color:#fff;
  text-decoration:none;
  cursor:pointer;
}


#dialog-overlay {
  position:fixed !important;
  position:absolute;
  z-index:999;
  top:0px;
  right:0px;
  bottom:0px;
  left:0px;
  background-color:#000;
   opacity: 0.10;
  display:none;
}