How to add jquery readmore function (expand/collapse) to magento CMS pages

I need a read more button link in my Magento CMS pages.

I got some long cms texts. I need a Read More link to collapse them.

The Read More link has to be always after the first paragraph or ofter 250 character or any other limitation. But it is better when I can place the link myself in the magento backend by adding some kind of shortcode. like [readmore] or something. Doesn't matter what.

this is an example what im trying to do. http://www.feestding.nl/themakleding...ween-kostuums/

example of the feature http://jedfoster.com/Readmore.js/

how can i do it?

Add your js library to your template head.phtml and then run it in footer.phtml of your active template