Reveal Text Onclick

I can very easily go and find some "reveal div text onclick" JavScripts, they are all over the internet (and I've tried dozens of them in different ways). But my problem is a little more difficult and I cant work out what to do. No matter how I try to implement such javascripts, I can't get a message to show up.
I have this slightly modified twitter "follow me" code:
From Here

Code (text):

<p><?php echo ‘<a…

Reveal Text Onclick

See original post by MrLeN