How to set a 'div' height same with his neighbor?

Question

I am using bootstrap as my CSS framework. Now I have some dynamic content in the left side div, and some static content in the right div. I want to the height of right side div auto change base on the height of left side div. Is that possible?

<div class="container-fluid">
  <div class="row-fluid">
    <div class="span5 offset1">
    <div class="well">
      Dynamic Content
    </div>
  </div>
  <div class="span5">
    <div class="well" style="height: 330px; overflow-x: hidden; overflow-y: scroll;">
      Static Content
    </div>
  </div>
</div>

Answer 1

You could do this

<div class="wrapper">
    <div class="dynamic">
        Dynamic Line <br />
        Dynamic Line <br />      
        Dynamic Line <br />
        Dynamic Line <br />      
        Dynamic Line <br />
        Dynamic Line <br />      
        Dynamic Line <br />
        Dynamic Line <br />      
    </div>
    <div class="static">
        Static<br />
        Static<br />        
    </div>
</div>

CSS

.wrapper {
    position: relative;
    width: 400px;
    overflow: auto;
}

.dynamic {
    position: relative;
    background-color: yellow;
    width: 200px;
}

.static {
    position: absolute;    
    background-color: orange;
    width: 200px;
    float: left;
    left: 200px;
    top: 0px;
    bottom: 0px;
    right: 0px;
}