function newImage(arg) {
rslt = new Image();
rslt.src = arg;
return rslt;
}

function bOver(image) {
document[image].src = eval(image +"_over.src");
}

function bOut(image) {
document[image].src = eval(image +"_out.src");
}

b1_out = newImage('images/button_chrono.gif');
b1_over = newImage('images/buttonover_chrono.gif');
b2_out = newImage('images/button_produits.gif');
b2_over = newImage('images/buttonover_produits.gif');
b3_out = newImage('images/button_store.gif');
b3_over = newImage('images/buttonover_store.gif');
b4_out = newImage('images/button_support.gif');
b4_over = newImage('images/buttonover_support.gif');
b5_out = newImage('images/button_contact.gif');
b5_over = newImage('images/buttonover_contact.gif');