<!DOCTYPE html>
<html>
<body>
<form id=formUsuario>
<input name=myName value=myValue>
</form>
<script type='text/javascript'>
var sAux={};
var frm = document.getElementById("formUsuario");
for (i = 0; i < frm.length; i++) {
sAux[frm[i].name] = frm[i].value;
}
console.log(sAux);
</script>
</body>
</html>