if (document.images) {
    projectsup       = new Image();
    projectsup.src   = "assets/menu_projects_fr.jpg" ;
    projectsdown     = new Image() ;
    projectsdown.src = "assets/menu_projects_fr_on.jpg" ;

    aboutup       = new Image();
    aboutup.src   = "assets/menu_about_fr.jpg" ;
    aboutdown     = new Image() ;
    aboutdown.src = "assets/menu_about_fr_on.jpg" ;

    workup       = new Image();
    workup.src   = "assets/menu_work_fr.jpg" ;
    workdown     = new Image() ;
    workdown.src = "assets/menu_work_fr_on.jpg" ;

    portfolioup       = new Image();
    portfolioup.src   = "assets/menu_portfolio.jpg" ;
    portfoliodown     = new Image() ;
    portfoliodown.src = "assets/menu_portfolio_on.jpg" ;
}
function buttondown( buttonname )
{
    if (document.images) {
      document[ buttonname ].src = eval( buttonname + "down.src" );
    }
}
function buttonup ( buttonname )
{
    if (document.images) {
      document[ buttonname ].src = eval( buttonname + "up.src" );
    }
}