div x内mutilple divs不能扩展其高度指定％？

我有一个侧边栏有很多嵌套的div来放置我的圆角corrners.but当我试图设置内容的div高度等于90％，它不扩展。什么是问题。我的html，身体有100％height.my div巢是这样的一些东西。div x内mutilple divs不能扩展其高度指定％？

<body> 
<div class="main">    //it contains header n content div,its height is 90% 
<div class="header"></div>  //its height is 10% of main div 
<div class="content">    //its height is 90% of main div 

<div class="vertical_navigation"> //its height is 99% of content div 

<div><div><div><div>    //thses divs are for rounded corner image concept 
<div> </div>      //this div contains the data.now its height is 80% but its not expanding?h 
            //i cant use min-height,its not working too.how to give height referenced to        //vertical navi div?? 
</div></div></div></div> 

</div> 

</div> 

</div> 
<footer></footer> 
</body>

来源

2011-01-21 Aakash Sahai

尝试发布您的*实际* HTML和CSS，而不是讨论它“有点”。另外，欢迎来到Stackoverflow！ =） – 2011-01-21 07:26:07