Please, if you don't know how to romanise, you better don't do it! I know it may sound a bit rude, but it's terrible when a person invents their own romanisation system.
You'd be better off learning how to type in 한글. There are lots of programs that you can use. Even if you don't want to install anything for whatever the reason, you can get free tools to type in 한글.
Here's one of them: