function maskInput(f, m) {
    function mask(e){
        var patterns = {"1": /[A-Z]/i, "2": /[0-9]/, "4": /[Àÿ]/i, "8": /./ },
            rules = { "a": 3, "A": 7, "9": 2, "C":5, "c": 1, "*": 8};
        function accept(c, rule){
            for(var i = 1, r = rules[rule] || 0; i <= r; i<<=1)
                if(r & i && patterns[i].test(c))
                    break;
                return i <= r || c == rule;
        }
        var k, mC, r, c = String.fromCharCode(k = e.key), l = f.value.length;
        (!k || k == 8 ? 1 : (r = /^(.)\^(.*)$/.exec(m)) && (r[0] = r[2].indexOf(c) + 1) + 1 ?
            r[1] == "O" ? r[0] : r[1] == "E" ? !r[0] : accept(c, r[1]) || r[0]
            : (l = (f.value += m.substr(l, (r = /[A|9|C|\*]/i.exec(m.substr(l))) ?
            r.index : l)).length) < m.length && accept(c, m.charAt(l))) || e.preventDefault();
    }
    for(var i in !/^(.)\^(.*)$/.test(m) && (f.maxLength = m.length), {keypress: 0, keyup: 1})
        addEvent(f, i, mask);
}
//Manipulador de Eventos: addEvent e removeEvent cross-browser
addEvent = function(o, e, f, s){
    var r = o[r = "_" + (e = "on" + e)] = o[r] || (o[e] ? [[o[e], o]] : []), a, c, d;
    r[r.length] = [f, s || o], o[e] = function(e){
        try{
            (e = e || event).preventDefault || (e.preventDefault = function(){e.returnValue = false;});
            e.stopPropagation || (e.stopPropagation = function(){e.cancelBubble = true;});
            e.target || (e.target = e.srcElement || null);
            e.key = (e.which + 1 || e.keyCode + 1) - 1 || 0;
        }catch(f){}
        for(d = 1, f = r.length; f; r[--f] && (a = r[f][0], o = r[f][1], a.call ? c = a.call(o, e) : (o._ = a, c = o._(e), o._ = null), d &= c !== false));
        return e = null, !!d;
    }
};
removeEvent = function(o, e, f, s){
    for(var i = (e = o["_on" + e] || []).length; i;)
        if(e[--i] && e[i][0] == f && (s || o) == e[i][1])
            return delete e[i];
    return false;
};

function verifica_data(obj) { 
 dia = (obj.value.substring(0,2)); 
 mes = (obj.value.substring(3,5)); 
 ano = (obj.value.substring(6,10)); 
 pr2 = true; 
 if ((dia) && (mes) && (ano)) {
  dia = eval(dia);
  mes = eval(mes);
  ano = eval(ano);
  // verifica o dia valido para cada mes 
  if ((dia < 1) || (((dia < 1 || dia > 30)) && ((mes == 4) || (mes == 6) || (mes == 9) || (mes == 11))) || (dia > 31)) { 
      pr2 = false; 
  } 
  // verifica se o mes e valido 
  if (mes < 01 || mes > 12 ) { 
      pr2 = false; 
  } 
  // verifica se e ano bissexto 
  if (mes == 2 && ( dia < 01 || dia > 29 || ( dia > 28 && (parseInt(ano / 4) != ano / 4)))) { 
      pr2 = false 
  } 
  if (ano < 1900) { pr2 = false; }
 } else { pr2 = false; }
 return pr2;
}