var teste = 0;
function trocar(id) {
    var el = document.getElementById(id);
    if (teste != 1) {
        el.src = "../../Content/Images/" + id + "At.png";
        teste = 1;
    }
}
function zerar(id) {
    var el = document.getElementById(id);
    if (teste != 0) {
        el.src = "../../Content/Images/" + id + "In.png";
        teste = 0;
    }
}