Related links embedded in pages....

Hey all, I'm sure you must have visited sites where articles on a page have links to place that explain what that word means.. eg: This is an article about a computer programming language called php which is taking web development to a different..... in the above snip of the article "computer programming" would be a link to some page that explains that, "php" could point to php.net or maybe have a dhtml popup that explains what P.H.P stands for etc etc Doing the above in a static .htm page is pretty easy, but doing this on a dynamically generated page is a bit hard.. as first you get the content from the DB, search for the words that match your (probably) array of "link words", replace the word with the code to generate a link or dhtml popup Thats putting it in the rawest sense...anybody know of any class, free piece of code, example functioning code etc that does this? Thanks, -Ryan