php - Dynamic chained select box

Question

Okay, so I have 2 select boxes on my page, the first with the name "select" with the following options hard-coded:

<select name="select" id="Testid">
        <option value="Misc">Misc...</option>
        <option value="Stunt">Stunt</option>
        <option value="deathmatches">Deathmatches</option>
        <option value="Car"> Car </option>
        <option value="Races">Races </option>
    </select>

The second select box however (named "deleteTp") I want to populate with a mysql table depending on the selection of the first select box. Each option value has a specific table in my database with the same name as the value.

I know how to populate the second select box with the database table, however I'm not sure how to do this dynamically depending on the users choice.

Please note I only know basic javascript.

And if you're wondering why I am trying to do this, it's because the second selectbox will be posted to an external page to delete the rows from the populated table.

Thank you for your time.

Answer 1

$.ajax({
  type: 'post',
  url: "ajax.php."
  data: { id:'your id here' } //your id is your select box selected id.
}).done(function() { 

});

on php side :

$id = $_REQUEST['id']; 
$json = array();
$sql = mysql_query("select * from yourdb where id = $id");
while ($row = mysql_fetch_assoc($sql)) {
    $json[] = $row;
}
echo json_encode($json);

ajax ref : http://api.jquery.com/jQuery.ajax/

json ref: http://en.wikipedia.org/wiki/JSON