I want to change the link-style for some of my links, like this:

a:hover
{
    /* These links will be blue when hovered-over */
    background-color: #3366FF;
}

However, I only want this to take effect in my Navigation Bar, and not for regular links.

I have tried variations on this:

#navbar a:hover
{
    /* These links will be blue when hovered-over */
    background-color: #3366FF;
}

With the intended meaning "this only applies to links with <div id="navbar">"
But it didn't work.

How can I set the style for only certain links, defined by the class or id of their container?