如何让2个浮动div具有相同的高度(How to have 2 floating divs have the same height)

 我有一个包含内包装的包装器，内包装器包含2个浮动div。 左边的内容比右边的内容多，所以它的高度大于右边的高度。 我要找的是两个容器都有相同的高度。 
 
 http://jsfiddle.net/Kh2Fh/ 
 
 我的HTML： 
 
<div id="wrapper">
    <div id="sub-menu">
        <div id="left-column" class="column">
            Agenda</br>
            Here I put some texte                                    
        </div>
        <div id="right-column" class="column">
            sdfdsf                          
        </div>
    </div>
</div>​
 
 我的css： 
 
body{
    background-color:#E5E5E5;}

#wrapper{
    background-color:#FFFFFF;
    width:800px;
    margin-left:auto;
    margin-right:auto;
    overflow:auto;}

#sub-menu{
    margin:10px;
    width:780px;
    position:relative;
    float:left;}

.column{      
    float:left;
height:100%;}

#left-column{
    width:500px;
    background-color:yellow;}

#right-column{
    width:280px;
    background-color:magenta;}

I have a wrapper containing an inner wrapper, and that inner wrapper contains 2 floating divs. The left one contains more content than the right one, so it's height is greater than the one on the right. What I am looking for is that both of the containers would have the same height.
 
http://jsfiddle.net/Kh2Fh/
 
My html:
 
<div id="wrapper">
    <div id="sub-menu">
        <div id="left-column" class="column">
            Agenda</br>
            Here I put some texte                                    
        </div>
        <div id="right-column" class="column">
            sdfdsf                          
        </div>
    </div>
</div>​
 
My css:
 
body{
    background-color:#E5E5E5;}

#wrapper{
    background-color:#FFFFFF;
    width:800px;
    margin-left:auto;
    margin-right:auto;
    overflow:auto;}

#sub-menu{
    margin:10px;
    width:780px;
    position:relative;
    float:left;}

.column{      
    float:left;
height:100%;}

#left-column{
    width:500px;
    background-color:yellow;}

#right-column{
    width:280px;
    background-color:magenta;}

原文：https://stackoverflow.com/questions/9648007