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_velo.gif');
b1_over = newImage('../images/buttonover_velo.gif');
b2_out = newImage('../images/button_presentation.gif');
b2_over = newImage('../images/buttonover_presentation.gif');
b3_out = newImage('../images/button_services.gif');
b3_over = newImage('../images/buttonover_services.gif');
b4_out = newImage('../images/button_news.gif');
b4_over = newImage('../images/buttonover_news.gif');
b5_out = newImage('../images/button_contact.gif');
b5_over = newImage('../images/buttonover_contact.gif');