function Mascara(e, src, mask) {
    if (window.event) {
        _TXT = e.keyCode;
    }
    else if (e.which) {
        _TXT = e.which;
    }

    if (_TXT > 47 && _TXT < 58) {
        var i = src.value.length;
        var saida = mask.substring(0, 1);
        var texto = mask.substring(i);

        if (texto.substring(0, 1) != saida) {
            src.value += texto.substring(0, 1);
        }

        if (texto.substring(1, 1) != saida) {
            src.value += texto.substring(1, 1);
        }

        return true;
    }
    else {
        return (_TXT == 8);
    }
}