jQuery addClass example
Change class name on click in jQuery
HTML
<div class="body">
<div class"wrapper">
this is body
</div>
<div class="dialog">
dialog
</div>
</div>
CSS
.body {
position:relative;
}
.dialog {
position: absolute;
background:rgba(0,0,0, 0.6);
color: white;
width: 300px;
height: 300px;
color:black;
left:0;
right:0;
top:0;
bottom:0;
margin: auto;
}