$( document ).ready( function() {

    $( "#primary-navigation > ul > li" ).mouseover( function() {
        
        $( this ).addClass( "hover" );
    
    } ).mouseout( function() { 
        
        $( this ).removeClass( "hover" );
        
    } );

} );

if ( jQuery.browser.msie && parseInt( jQuery.browser.version, 10 ) == 6 ) {
  try {
    document.execCommand( "BackgroundImageCache", false, true );
  } catch( err ) {}
}