Some Edition crontab

Hello

First things apologize for my bad english ..
today i fixed alot cron job delete issues and added 15 mins cron tab
when add cron job with cron manager .. its Okie
then i delete cron job in my panel .. its deleted on panel ..
but still not delete on root SQL DB .. sentora_core => x_cronjobs list
then i delete some core from etc/sentora/panel/modules/cron/code/controller.ext.php

Here how to fix

PHP Code:
static function doDeleteCron()
    {
        global $zdbh;
        global $controller;
        runtime_csfr::protect();
        $currentuser = ctrl_users::GetUserDetail();
        $sql = "SELECT COUNT(*) FROM x_cronjobs WHERE ct_acc_fk=:userid AND ct_deleted_ts IS NULL";
        $numrows = $zdbh->prepare($sql);
        $numrows->bindParam(':userid', $currentuser['userid']);
        if ($numrows->execute()) {
            if ($numrows->fetchColumn() <> 0) {
                $sql = $zdbh->prepare("SELECT * FROM x_cronjobs WHERE ct_acc_fk=:userid AND ct_deleted_ts IS NULL");
                $sql->bindParam(':userid', $currentuser['userid']);
                $sql->execute();
                while ($rowcrons = $sql->fetch()) {
                    if (!fs_director::CheckForEmptyValue($controller->GetControllerRequest('FORM', 'inDelete_' . $rowcrons['ct_id_pk'] . ''))) {

                        $sql2 = $zdbh->prepare("UPDATE x_cronjobs SET ct_deleted_ts=:time WHERE ct_id_pk=:cronid");
                        // delete above and replace with below
                        $sql2 = $zdbh->prepare("DELETE FROM x_cronjobs WHERE ct_id_pk=:cronid");

                        $sql2->bindParam(':cronid', $rowcrons['ct_id_pk']);

                        $sql2->bindParam(':time', time());   // and delete this one
                        $sql2->execute();
                        self::WriteCronFile();
                       self::$ok = TRUE;
                        return;
                    }
                }
            }
        }
        self::$error = TRUE;
        return;
    } 

15 Mins cronjob added

static function getCreateCron()

add this line under of Every 10 minutes

PHP Code:
$line .= "<option value=\"0,15,30,45 * * * *\">" . ui_language::translate("Every 15 minutes") . "</option>"; 

static function TranslateTiming($timing)

add this line under of Every 10 minutes

PHP Code:
if ($timing == "0,15,30,45 * * * *") {
            $retval = "Every 15 minutes";
        } 

//// done ////

If somethings wrong pls help me admin !