if (document.images) {
    aboutbuttonup       = new Image();
    aboutbuttonup.src   = "pictures/icon/about.gif" ;
    aboutbuttondown     = new Image() ;
    aboutbuttondown.src = "pictures/icon/aboutOver.gif" ;
    
    contactbuttonup       = new Image();
    contactbuttonup.src   = "pictures/icon/contact.gif" ;
    contactbuttondown     = new Image() ;
    contactbuttondown.src = "pictures/icon/contactOver.gif" ;
    
    homebuttonup       = new Image();
    homebuttonup.src   = "pictures/icon/home.gif" ;
    homebuttondown     = new Image() ;
    homebuttondown.src = "pictures/icon/homeOver.gif" ;
    
    pricelistbuttonup       = new Image();
    pricelistbuttonup.src   = "pictures/icon/pricelist.gif" ;
    pricelistbuttondown     = new Image() ;
    pricelistbuttondown.src = "pictures/icon/pricelistOver.gif" ;
    
    productsbuttonup       = new Image();
    productsbuttonup.src   = "pictures/icon/products.gif" ;
    productsbuttondown     = new Image() ;
    productsbuttondown.src = "pictures/icon/productsOver.gif" ;
    
    servicecallsbuttonup       = new Image();
    servicecallsbuttonup.src   = "pictures/icon/servicecalls.gif" ;
    servicecallsbuttondown     = new Image() ;
    servicecallsbuttondown.src = "pictures/icon/servicecallsOver.gif" ;
    
    termsbuttonup       = new Image();
    termsbuttonup.src   = "pictures/icon/terms.gif" ;
    termsbuttondown     = new Image() ;
    termsbuttondown.src = "pictures/icon/termsOver.gif" ;
    
    employmentbuttonup       = new Image();
    employmentbuttonup.src   = "pictures/icon/employment.gif" ;
    employmentbuttondown     = new Image() ;
    employmentbuttondown.src = "pictures/icon/employmentDown.gif" ;
    
    configbuttonup       = new Image();
    configbuttonup.src   = "pictures/icon/configurator.gif" ;
    configbuttondown     = new Image() ;
    configbuttondown.src = "pictures/icon/configuratorOver.gif" ;
    
}

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" );
      
     }   
 }