• Go To Blogger >> Layout >> Add a Gadget
• Choose HTML/JavaScript
• Paste The Following Code in Content Box

<!-- Facebook Popup Widget START --><!-- Brought to you by www.mrad4tech.tk  -->
<script src='http://ajax.googleapis.com/ajax/libs/jquery/1.7.2/jquery.min.js' type='text/javascript'></script>
<style>
#fanback {
display:none;
background:rgba(0,0,0,0.8);
width:100%;
height:100%;
position:fixed;
top:0;
left:0;
z-index:99999;
}
#fan-exit {
width:100%;
height:100%;
}
#Burptech {
background:white;
width:420px;
height:270px;
position:absolute;
top:58%;
left:63%;
margin:-220px 0 0 -375px;
-webkit-box-shadow: inset 0 0 50px 0 #939393;
-moz-box-shadow: inset 0 0 50px 0 #939393;
box-shadow: inset 0 0 50px 0 #939393;
-webkit-border-radius: 5px;
-moz-border-radius: 5px;
border-radius: 5px;
margin: -220px 0 0 -375px;
}
#Burp {
float:right;
cursor:pointer;
background:url(https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEit7YaHHu069BjWEzIJUL7riZxKy_CkXRcUeBr58rcz7d3eft3mGnKxQn5zdRuyL1u7NlFAQuSdKNTU0AYQKsQiWFgJnQZSskt9ukUCgLQ5t6RhiVmdWHVku0kTULJZOOUPmmnF70MXcFm6/s1600/Burp.png) repeat;
height:15px;
padding:20px;
position:relative;
padding-right:40px;
margin-top:-20px;
margin-right:-22px;
}
.remove-borda {
height:1px;
width:366px;
margin:0 auto;
background:#F3F3F3;
margin-top:16px;
position:relative;
margin-left:20px;
}
#linkit,#linkit a.visited,#linkit a,#linkit a:hover {
color:#80808B;
font-size:10px;
margin: 0 auto 5px auto;
float:center;
}
</style>
<script type='text/javascript'>
//<![CDATA[
jQuery.cookie = function (key, value, options) {
// key and at least value given, set cookie...
if (arguments.length > 1 && String(value) !== "[object Object]") {
options = jQuery.extend({}, options);
if (value === null || value === undefined) {
options.expires = -1;
}
if (typeof options.expires === 'number') {
var days = options.expires, t = options.expires = new Date();
t.setDate(t.getDate() + days);
}
value = String(value);
return (document.cookie = [
encodeURIComponent(key), '=',
options.raw ? value : encodeURIComponent(value),
options.expires ? '; expires=' + options.expires.toUTCString() : '', // use expires attribute, max-age is not supported by IE
options.path ? '; path=' + options.path : '',
options.domain ? '; domain=' + options.domain : '',
options.secure ? '; secure' : ''
].join(''));
}
// key and possibly options given, get cookie...
options = value || {};
var result, decode = options.raw ? function (s) { return s; } : decodeURIComponent;
return (result = new RegExp('(?:^|; )' + encodeURIComponent(key) + '=([^;]*)').exec(document.cookie)) ? decode(result[1]) : null;
};
//]]>
</script>
<script type='text/javascript'>
jQuery(document).ready(function($){
if($.cookie('popup_user_login') != 'yes'){
$('#fanback').delay(1000).fadeIn('medium');
$('#Burp, #fan-exit').click(function(){
$('#fanback').stop().fadeOut('medium');
});
}
$.cookie('popup_user_login', 'yes', { path: '/', expires: 7 });
});
</script>
<div id='fanback'>
<div id='fan-exit'>
</div>
<div id='Burptech'>
<div id='Burp'>
</div>
<div class='remove-borda'>
</div>
<iframe allowtransparency='true' frameborder='0' scrolling='no' src='//www.facebook.com/plugins/likebox.php?
href=https://www.facebook.com/Mrad4Tech&width=402&height=255&colorscheme=light&show_faces=true&show_border=false&stream=false&header=false'
style='border: none; overflow: hidden; margin-top: -19px; width: 402px; height: 230px;'></iframe><center>
<span id="linkit">Powered by <a href="http://www.Mrad4Tech.tk">Mrad4Tech.tk</a> - <a href="http:/www.Mrad4Tech.tk">Facebook Like Box</a></span></center>
</div>
</div>

Enter your Facebook Page Name

replace Mrad4Tech  with your site’s facebook page URL or id

Popup every time the page loads 
By default, the like box widget only shows up the first time the user visits your page. If you would like the facebook box to popup every time the page loads, then remove this line of code:

$.cookie('popup_user_login', 'yes', { path: '/', expires: 7 });