<div style="display:none">$NAME_FL$</div>
<input type="text" id="edit_name" onkeyup="save_name();" placeholder="Имя">
<input type="text" id="edit_surname" onkeyup="save_name();" placeholder="Фамилия">
<input type="text" id="edit_thirdname" onkeyup="save_name();" placeholder="Отчество">

<script>
function load_name() {
var names = $('#siF16').val().split(' ');
var f_name = names[0];
var s_name = names[1];
var t_name = names[2];
$('#edit_name').val(f_name);
$('#edit_surname').val(s_name);
$('#edit_thirdname').val(t_name);
}

function save_name() {
var f_name = $('#edit_name').val();
var s_name = $('#edit_surname').val();
var t_name = $('#edit_thirdname').val();
var full_name = f_name+' '+s_name+' '+t_name;
$('#siF16').val(full_name);
}

load_name();
</script>