Question

Below is my form.
Using jQuery I load a <select> element based on value on previous <select>. However when I send the form the value of the dynamically added <select> (add_student_contact_id) is not beeing $_POST‘ed. Is it because it’s beeing added after the page load? Is there any way to solve it?

students.php

    <form action='../insert.php' method='post' name='add_student'>

    <!-- This is generated by PHP -->

    <select id='add_student_customer'>
        <option>Select one...</option>
        <option value='1'>First value</option>
        <option value='2'>Second value</option>
        <option value='3'>Third value</option>
    </select>

    <!-- Here a select element will load from another PHP-file based on values from the previous select -->
    <div id='add_student_contactperson_container'></div>

    <!-- This is generated on page load but will not be visible until we select something in the previous select -->
    <select id='add_student_course'>
      <option>Select something...</option>
      <option value='1'>An option</option>
      <option value='2'>A second option</option>
    </select>
    </form>

jQuery

<script>
$(document).ready(function() {
$("#add_student_course_container").hide();
$(document).on("change", "#add_student_customer_select", function(){
        var row_id = $(this).val();
        $.ajax({
            url: "/load_customer_contacts.php",
            data: { 'customer_id':row_id },
            success: function(data){
                $("#add_student_contactperson_container").html(data);
            }
        });
    });
});
$(document).on("change", "#add_student_contact", function(){
   $("#add_student_course_container").show();
});
</script>

/load_customer_contacts.php

if (isset($_GET['customer_id'])) {

/* SQL stuff */

echo "<select name='add_student_contact_id'>\n";
    while ($row = mysql_fetch_assoc($sql)) {
        echo "<option value='".$row['contact_id']."'>".$row['name']."</option>\n";
    }
echo "</select>\n";
}

Answer 1

One possible reason is that $row['contact_id'] doesn’t have a value when injected into the page. Another reason is you are missing a name attribute. This would mean the browser is either:

• Sending the blank value
• Omitting it completely

If you could check that and post back we could provide some more help.