How to change the currcucy format 00,00 to 00.00

-- url of the page with the problem -- : choysir.com/hikashop-menu-for-categories...ng/category/14-.html

I come from HK, the currcucy format shall be 100.00 not 100,00.

How to change the "," to "." as per attached picture.

In the backend, go to -> System -> Currencies, find the HKD and open it. In the right pane you'll find "Decimal separation", change it from "," to ".", then save. That's it.
But while you're at it, and if you prefer, you can change the "Group separator" from a space to "," as well.

Hint: Check out all the the backend settings, there's a lot you can configure for your very own needs. Much is self-explanatory, for others you have (1) the "Help" button in the top toolbar in the backend, (2) the documentation under "Support" here, (3) the "Search" function here in the forums.

Thanks. Got it.