I can't get the MarkItUp to display bbcode in the preview

I want to use markItUp to allow users to format their text using bbcode, but the preview isn't working.

I've downloaded markItUp 1.1.8 from the site and tested this locally. The default behaviour is to use HTML code for formatting, and pressing preview renders the code as html and displays the formatting.

I've downloaded the "basic bbcode set" from the same markItUp website and put th开发者_Python百科is folder into the "sets" folder as instructed. I have changed the path of the js file from markitup/sets/default/set.js to markitup/sets/bbcode/set.js as instructed. And the same with the css file.

If I test the markItUp editor now it allows me to add bbcode to my text, but if I press preview, it doesnt render my bbcode as formatted text.

I read on the markItUp website that I have to use a bbcode parser to make the preview work, so I have downloaded "markItUp! Php BBCode Parser" from the website. I've placed this in the root directory of my markItUp files, and in the jquery.markitup.js file I've written the path to the parser as instructed. The path I've used is ~/markitup.bbcode-parser.php

But this isn't working. The preview is just displaying nonsense if I test locally, or a plain white box if I test in my localhost.