$user = new User($db->conn);
$vendor = new Vendor($db->conn);
$item = new Item($db->conn);
$isAvailable = false;
if (!isset($_POST['type'])) {
echo json_encode(array('valid' => $isAvailable));
exit;
}
switch ($_POST['type']) {
case 'email':
if ($user->check_email($_POST['email'])) {
$isAvailable = true;
}
break;
case 'phone':
if ($user->check_phone($_POST['phone'])) {
$isAvailable = true;
}
break;
case 'vendor_email':
if ($vendor->check_email($_POST['email'])) {
$isAvailable = true;
}
break;
case 'delete_item':
if ($item->delete($_POST['object_id'])) {
$isAvailable = true;
}
break;
case 'delete_user':
if ($user->delete($_POST['object_id'])) {
