CSS classes: base + optional. How to determine?

Question

I have a div:

<div class="navigation mainPage"></div> 

I need to point out that: every DIV that has a class of "navigation" and a class of "mainPage" should have a "width: 999px".

Is it possible? THX

Answer 1

 .navigation.mainPage { width: 999px; } 

Answer 2

You can try

 .navigation.mainPage { width: 999px; } 

but this one does not work in IE6 . You can try to get by doing

 <div class="navigation navigation-mainPage"></div> 

and then CSS

 .navigation-mainPage { width: 999px; } 

Even if this is not the most pleasant solution, but I do not know anyone else.

Answer 3

Try the following:

 .navigation, .mainPage{ width:999px; overflow:hidden;}