I have a problem in the selection box, I can't see the vertical scrollbar in the right-hand site, it makes me difficult to scroll down in the selection box to choose the option. Hope someone can guide me how to solve it.
<style>
#parentid{
max-height:200px;
overflow:auto;
size:10;
}
</style>
<select onchange="getComboA(this)" class="form-control blank" id="parentid" name="parentid" title="parentid">
<option value="please_select">--Sila Pilih--</option>
<option value="0">New Category</option>
<?php
$sql_incharge = 'select * from filing_code_management where status=1 and is_approved = 1 and category_id in (1,2,3,4)ORDER BY id ASC';
$arr_incharge = db_conn_select($sql_incharge);
foreach ($arr_incharge as $rs_incharge) {
$folder_location = $rs_incharge['folder_location'];
$function_code_select = $rs_incharge['function_code'];
$function_name_select = $rs_incharge['function_name'];
$activity_code_select = $rs_incharge['activity_code'];
$activity_name_select = $rs_incharge['activity_name'];
$name_select = $rs_incharge['name'];
$id_select = $rs_incharge['id'];
$root = $rs_incharge['id_root'];
$category_id = $rs_incharge['category_id']; // get category_id here
// save the data here↓↓ in data attributes
echo "<option value='{$id_select}' data-cat_id='{$category_id}' data-root='{$root}'>{$name_select}</option>";
}
?></select>

I want the expected result like below the sample picture:

Thanks in advance.