Selecting elements with multiple classes

Came across a problem today that meant I needed to select all elements that had two particular classes.

I needed to apply my styles to any element with class=”className className2″.  This is easily done by using:

className.className2{ styles }

Fortunately this was for an intranet project, as IE6 and lower do not support selecting like this. I believe they will only read the last part and apply the styles to className2.