【代码片段】遮罩层
$(function() { var h = $(document).height()+"px"; var w = $(document).width()+"px"; $('#t').css({ height:h,width:w}); }); <div id="t" style="border:solid red 1px;filter:alpha(opacity=0.5);opacity:0.5;"> 111111 </div>
$(function() { var h = $(document).height()+"px"; var w = $(document).width()+"px"; $('#t').css({ height:h,width:w}); }); <div id="t" style="border:solid red 1px;filter:alpha(opacity=0.5);opacity:0.5;"> 111111 </div>