html
<div class='bg'>
<div class='show'>内容</div>
</div>
css
.bg{
display: none;
position: absolute;
top: 0%;
left: 0%;
width: 100%;
height: 100%;
background-color: rgba(0,0,0,0.3);
z-index:1001;
}
.show{
display: block;
position: absolute;
margin:auto;
top:0;
left:0;
right:0;
bottom:0;
width: 600px;
height: 300px;
padding: 8px;
border: 8px solid #E8E9F7;
background-color: white;
z-index:1008;
overflow: auto;
}
js
function showselect(){
$('.select_bg').css("display","block");
}
function closeselect(){
$('.select_bg').css("display","none");
}