网页遮罩效果，可使整个网页变半透明，中间弹出一窗口。
<style> .bg{position:absolute;z-index:999;filter:alpha(opacity=50);background:#666;opacity: 0.5;-moz-opacity: 0.5;left:0;top:0;height:99%;width:100%;} .beian_winBG { MARGIN-TOP: -100px; LEFT: 50%; MARGIN-LEFT: -190px; WIDTH: 376px; POSITION: absolute; TOP: 50%; HEIGHT:200px;border:#666666 1px solid;z-index: 1000; } </style> <div id="alert_win" style="display:none;"> <div id="mask" style="top:0;left:0;position: absolute;z-index:1000;" class="bg"></div> <DIV class=beian_winBG id=beian_popup><!--弹出框--> <div id="divOneStep" style="z-index:1002;width:100%;height:200px;background: #fff;position:absolute;"> <div style="width:100%;background:#f1f1f1;height:30px;light-height:30px;border-bottom:#666666 1px solid;text-align:right;"><a href="javascript:;" onClick="alert_win.style.display='none';">点此关闭</a> </div> <div>文字内容文字内容文字内容文字内容文字内容文字内容文字内容文字内容文字内容</div> </div> <div style="z-index:1001;position:absolute;"><iframe id="frmOneStep" width="100%" height="200" frameborder="0" scrolling="no" src="about:blank"></iframe></div> </DIV> </div> <a href="javascript:;" onClick="alert_win.style.display='block';">显示</a> <p>alksdfjsdkal;jsdakljfdsalk;jdlks;ajdfslka;jfdslka;jfdasf</p> <p>alksdfjsdkal;jsdakljfdsalk;jdlks;ajdfslka;jfdslka;jfdasf</p>
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