var btHome = new Image();
btHome.src = "imgs/menu/menu_over_02.jpg";

var btAgencia = new Image();
btAgencia.src = "imgs/menu/menu_over_03.jpg";

var btPortfolio = new Image();
btPortfolio.src = "imgs/menu/menu_over_04.jpg";

var btSolucoes = new Image();
btAgencia.src = "imgs/menu/menu_over_05.jpg";

var btContato = new Image();
btAgencia.src = "imgs/menu/menu_over_06.jpg";

function menuOver(target, targetSrc)
{
    document.getElementById(target).src = targetSrc;
}