Blink

by OwenMelbz

HTML

<div class="b1"></div>
<div class="b2"></div>

CSS

body {
    background-image: url('http://attachments.techguy.org/attachments/66283d1129995795/desktop-screenshot-windows-installer-bootup.jpg');
    background-size:100% auto;
    background-repeat:no-repeat;
    margin:0;
    padding:0;
}

.b1, .b2 {
 position: absolute;
    width:100%;
    height:50%;
    background: black;
    top:0;
    left:0;
}
.b2 {
    bottom:0;
    top: auto;
}
}

JavaScript

$(function(){
    
    var b1 =  ($(window).height()/2)*-1;
    $('.b1').css('top', b1);
    
    var b2 =  ($(window).height()/2)*-1;
    $('.b2').css('bottom', b1);
    
    var blink = setInterval(function(){
        
        $('.b1').animate({'top':0}, {duration: 100, queue: false, complete: function(){
            $('.b1').animate({'top':b1}, 100);
        }});
        
        $('.b2').animate({'bottom':0}, {duration: 100, queue: false, complete: function(){
            $('.b2').animate({'bottom':b2}, 100);
        }});
        
    }, 5000);
    
});