function checkForm() {
	var form = document.getElementById("form_contato");
	if (form.nome.value == "") {
		window.alert("Por favor, informe o nome.");
		form.nome.focus();
		return false
	}
	else if (!/[A-Za-z0-9_.-]+@([A-Za-z0-9_]+\.)+[A-Za-z]{2,4}/.test(form.email.value)) {
		window.alert("Por favor, informe um e-mail válido.");
		form.email.focus();
		return false
	}
	else if (form.assunto.value == "") {
		window.alert("Por favor, informe o assunto.");
		form.assunto.focus();
		return false
	}
	else if (form.mensagem.value == "") {
		window.alert("Por favor, informe a mensagem.");
		form.mensagem.focus();
		return false
	}
	return true;
}

function checkFone(obj){
    var v = obj.value;
    v = v.replace(/\D/g,"");
    v = v.replace(/^(\d\d)(\d)/g,"($1) $2");
    v = v.replace(/(\d{4})(\d)/,"$1-$2");
    obj.value = v;
}

function checkLetra(obj){
    var v = obj.value;
    v = v.replace(/\d/g,"");
    obj.value = v;
}
    
function checkCPF(obj){
    var v = obj.value;
    v = v.replace(/(\.|\(|\)|\/|\-| )+/g,'');
    var tam = v.length + 1;
    if (tam > 3 && tam < 7)
            obj.value = v.substr(0,3) + '.' + v.substr(3, tam);
    if (tam >= 7 && tam < 10)
            obj.value = v.substr(0,3) + '.' + v.substr(3,3) + '.' + v.substr(6,tam-6);
    if (tam >= 10 && tam < 12)
            obj.value = v.substr(0,3) + '.' + v.substr(3,3) + '.' + v.substr(6,3) + '-' + v.substr(9,tam-9);
    if (tam > 12)
            obj.value = obj.value.substr(0,obj.value.length-1);
}

function checkCEP(obj){
    var v = obj.value;
    v = v.replace(/(\.|\(|\)|\/|\-| )+/g,'');
    var tam = v.length + 1;
    if (tam > 5 && tam < 7)
            obj.value = v.substr(0,5) + '-' + v.substr(5, tam);
    if (tam > 9)
            obj.value = obj.value.substr(0,obj.value.length-1);
}

function checkData(obj){
    var v = obj.value;
    v = v.replace(/(\.|\(|\)|\/|\-| )+/g,'');
    var tam = v.length + 1;
    if (tam>2 && tam<5)
       v = v.substr(0,2) + '/' + v.substr(2, tam);
    if (tam > 4 && tam < 11)
       v = v.substr(0,2) + '/' + v.substr(2,2) + '/' + v.substr(4,tam-4);
    obj.value = v;
}