Automatic change of line height

[guilherme]

There's a Sidebar-line. What's interesting is, how do this line automatically change the altitude when adding posts or some text to the Sidebar?

[Cleofas]

<div id="div_with_text"></div>

CSS:

If the column on the right:

#div_with_text {
border-left: 1px solid #808080;

}

For left column:

#div_with_text {

border-right: 1px solid #808080;

}