How to populate 2 selectbox from database using php and ajax - php

Question

I have a problem, how to pass an argument with ajax in url: <?php echo base_url() . 'user_m/getAdministrator'; ?>" argument,
Because I tried to populate a selectbox based on another but I didn't have success.
html:
<div class="form-group">
<label>Denumirea intreprinderii:</label>
<select class="form-control marg-left-10" id="firm">
<?php if($all_firms): ?>
<?php foreach($all_firms as $firm): ?>
<option value="<?php echo $firm['id_firm']; ?>"><?php echo $firm['name_firm']; ?></option>
<?php endforeach; ?>
<?php endif; ?>
</select>
</div>
<div class="form-group">
<label>Administrator</label>
<select class="form-control marg-left-10" id="admin">
</select>
</div>
php:
public function getAdministrator()
{
$id_firm = $_POST['id_firm'];
$this->load->database();
$sql = $this->db->query("SELECT * FROM users,firms WHERE firms.id_firm = users.fk_firm and users.id = ");
while($row=mysql_fetch_array($sql))
{
$id=$row['id'];
$data=$row['name'];
echo '<option value="'.$id.'">'.$data.'</option>';
}
return $this;
}
script:
$(document).ready(function()
{
$("#firm").change(function()
{
var id_firm=$(this).val();
var dataString = 'id_firm='+ id_firm;
$.ajax
({
type: "POST",
url: "<?php echo base_url() . 'user_m/getAdministrator'; ?>",
data: dataString,
cache: false,
success: function(html)
{
$("#admin").html(html);
}
});
});
});
Help me please.The first select box gets populated but the second doesn't.Please Help me.Exist a method to pass an argument to user_m/getAdministrator method? HELP ME PLEASE GUYS!!!!!

Answer 1

Php in js is not a good practice, try to write this on your main php file before calling the script
<script>
var base_url = "<?=base_url()?>";
</script>
and then in your js file:
$.ajax
({
type: "POST",
url: base_url+"user_m/getAdministrator",
data: dataString,
cache: false,
success: function(html)
{
$("#admin").html(html);
}
});
also, you can send data this way:
data: { id_firm: id_firm },