Dreamweaver教程：实现网页中间弹出窗口案例
我们一起来看看下面的代码：
<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>21视频教程网网帮您解决！</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>
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