function mascara(src, mask){
<!-- OnKeyPress="mascara(this, '#####-###')" -->
    if (event.keyCode != 8) {
        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);
        }
    }
}