navegador = (((navigator.appName == "Netscape") && 
(parseInt(navigator.appVersion) >= 3 )) || 
((navigator.appName == "Microsoft Internet Explorer") && 
(parseInt(navigator.appVersion) >= 4 )))
if (navegador)
{

desligadoimg0 = new Image()
desligadoimg0.src = "menu/logo.jpg"
ligadoimg0 = new Image()
ligadoimg0.src = "menu/logo2.jpg"

desligadoimg1 = new Image()
desligadoimg1.src = "menu/home.jpg"
ligadoimg1 = new Image()
ligadoimg1.src = "menu/home2.jpg"

desligadoimg2 = new Image()
desligadoimg2.src = "menu/portifolio.jpg"
ligadoimg2 = new Image()
ligadoimg2.src = "menu/portifolio2.jpg"

desligadoimg3 = new Image()
desligadoimg3.src = "menu/contato.jpg"
ligadoimg3 = new Image()
ligadoimg3.src = "menu/contato2.jpg"

}
function escolha(numeroimagem,nome){if (navegador){document.images[numeroimagem].src = eval(nome + ".src")}}