var byID = true;
var json = $('#form_id').getJSON( byID );

var json = $("#form_id").getJSON();

var lancamento = {
    empresa: {id: 2, name: "Teste"},
    partidas: [
        {conta: {codigo:"1.02.0002", nome: "Compras"}, natureza: "1"},
        {conta: {codigo:"1.02.0001", nome: "Banco"}, natureza: "-1"}
    ],
    description: "Teste",
    value: "125,67",
    date: "12/03/1999"
};
var byID = true;
$('#form_id').populate( lancamento, byID );

var lancamento = {
    empresa: {id: 2, name: "Teste"},
    partidas: [
        {conta: {codigo:"1.02.0002", nome: "Compras"}, natureza: "1"},
        {conta: {codigo:"1.02.0001", nome: "Banco"}, natureza: "-1"}
    ],
    description: "Teste",
    value: "125,67",
    date: "12/03/1999"
};
$("[name='form_name'").populate(lancamento);

var script = document.createElement('script');
script.onload = function() {
   var jsonFormScript = document.createElement("script");
   //source version
   jsonFormScript.src = "https://raw.github.com/milfont/jsonform/master/lib/jsonform.js";
   //minified version
   //jsonFormScript.src = "https://raw.github.com/milfont/jsonform/master/minified/jsonform.min.js";
  document.body.appendChild(jsonFormScript);
};
script.src = "https://raw.github.com/milfont/jsonform/master/vendor/jquery-1.7.1.min.js";
document.getElementsByTagName('head')[0].appendChild(script);