public function ajax_find_students()
 {
     $lib = new supervisor_lib_ad();
     $lib->ajax_find_students();
 }
<?php

$use = new class_loader();
$use->use_lib('admin/supervisor_lib_ad');
$lib = new supervisor_lib_ad();
$data = $lib->find($_GET['id']);
if ($data == false) {
    redirect('admin/supervisor');
}
$data = array_shift($data);
?>
<div class="col-sm-12 main">
    <div class="row page-header">
        <div class="col-sm-2"><h5><b><a href="<?php 
echo site_url('admin/supervisor');
?>
">Supervisor : </a> </b> </h5></div>
        <div class="col-sm-2"><h5> <?php 
echo $data[tpl_supervisor::name()];
?>
 </h5></div>
    </div>
    <div class="row">
        <div class="col-sm-6">
            <h3 class="page-header">Number Students</h3>
            <div class="table-responsive">
                <table id="table_srudent" data-toggle="table"
                       data-url="<?php 
echo site_url('admin/supervisor/ajax_students');
?>
"
                    <div class="form-group">
                        <label>College <?php 
echo tpl_supervisor::supervisor();
?>
 : </label>
                        <select name="<?php 
echo tpl_supervisor::supervisor() . '_' . tpl_supervisor::id_university() . '_update';
?>
"
                                id="<?php 
echo tpl_supervisor::supervisor() . '_' . tpl_supervisor::id_university() . '_update';
?>
"
                                class="form-control">
                            <?php 
$new = new supervisor_lib_ad();
echo $new->find_university();
?>
                        </select>
                    </div>

                    <button type="submit" class="btn btn-success" id="update" name="update">Save</button>
                </form>
                </br>
                </br>
                <div class="" id="result_massages_update"></div>
            </div>
        </div>
    </div>
</div>