JS实现遮罩层效果的简单实例_javascript技巧

function show(){

var cover = document.getElementById("cover");

cover.style.width = document.documentElement.scrollWidth+"px";

cover.style.height = document.documentElement.scrollHeight+"px";

cover.style.display = "block";

}

#cover{

background:gray;

position:absolute;

left:0px;

top:0px;

display:none;

z-index:20;

filter:alpha(opacity=60);

opacity:0.6 !important;

}