Ways to create combobox using AJAX to fill

I currently have a regular HTML combobox:

<select name="nomeCombox1" id="nomeCombox1" class="select"> 
    <option value="0" selected="selected">Selecione box1</option>
    <?php
    $res = odbc_exec($conexao, "Select DISTINCT desc from tab1");
    while ($row = odbc_fetch_array($res)) {
        echo "<option name='nomeCombox1' value='" . $row['desc'] . "'>" . $row['desc'] . "</option>";
    }
    ?>
</select>

This combo is correctly fetching the data.

In the next step, I have a JS where I look for what was selected and play in a new combobox:

$("#nomeCombox1").change(function () {
    var idCombox1 = $(this).val();
    $.ajax({
        dataType: 'json',
        url: "js/ajaxBuscar.php",
        data: {idCombox1: idCombox1},
        success: function(data) {
            var q = '<select name="idCombox2" id="idCombox2" class="select"> <option value="0">Escolha</option>';
            for(i=0; i < data.length; i++ ){
                q += '<option value=' + data[i].idCombox2 + '>' + data[i].descricao + '</option>';
            }
            q += '</select>';
            $('#div1').html(q);
        }, error: function(request, status, error) {
            alert(request.responseText);
        }
    });
});

These codes are all 100% working. My main question would be: How can I create this Combobox2 without being via JS? That is, without having to play $('#div1').html(q) . Is there another way?

I'm wanting another way because I have a function in JS where I would have to check this value of that second combobox and fill an input with the result of another AJAX. When I put combobox2 straight into HTML it works. What I'm guessing is that the moment the page loads, there is no such second combo, so JS can not execute correctly.