function validaForm(form) {
    for (var i = 0; i < document.getElementById(form).elements.length; i++) {
        
        var nomeObj = document.getElementById(form).elements[i].name;
        var idObj 	= document.getElementById(form).elements[i].id;
		var relObj 	= document.getElementById(form).elements[i].getAttribute('rel');
				
		if ((relObj == "email")) {
			expressao = /^\w+([-+.]\w+)*@\w+([-.]\w+)*\.\w+([-.]\w+)*$/i;
			if(!expressao.test(document.getElementById(form).elements[i].value)){
				alert(document.getElementById(form).elements[i].title);
				document.getElementById(form).elements[i].value = "";
				document.getElementById(form).elements[i].className = "campo-requerido";
				document.getElementById(form).elements[i].focus();
				return false;
			}
		}else if (relObj == "required") {
			if((document.getElementById(form).elements[i].value == null) || (document.getElementById(form).elements[i].value == "")){
				alert(document.getElementById(form).elements[i].title);
				document.getElementById(form).elements[i].className = "campo-requerido";
				document.getElementById(form).elements[i].focus();
				return false;
			}
		}
    }
    return true;
}