Conditional Menu for Posts Within Category

Hi,

I need to display a different menu for a certain category AND posts within that category. I have been looking for a code or plugin (although I would rather use code) and can’t seem to find something that will display the new primary nav for posts within the category, only the category page itself. I tried this code and it did nothing.

<?php
if(has_nav_menu('primary'))
{
}
   if(is_category(meijer-2)){
    $locationMenu=meijer
?>
<?php
                wp_nav_menu( array(
			'menu' => $locationMenu,
                        'theme_location'=> 'primary',
                        'container'     => false,
                        'menu_id'       => 'nav',
                        'fallback_cb'   => 'wp_page_menu'
                    ) );
} else
?>