Hi,
So please check your PHP error log.
If you have a full blank page, it is a PHP fatal error.
If your page is "empty" but not full blank, it could be an "return" or an "exit/die" problem.
Like that with your code, I can't tell you what's wrong ; I take a look and does not see like that, a mistake.
Regards,
Jerome - Obsidev.com
HikaMarket & HikaSerial developer / HikaShop core dev team.
Also helping the HikaShop support team when having some time or couldn't sleep.
By the way, do not send me private message, use the "contact us" form instead.