Is there any WordPress plugin to show/hide a serial key in a post?

I'm looking for a WordPress plugin that hides a serial key in a post by default and shows when the user clicks the show button.

I used jQuery to do this, but the serial key can be easily revealed by viewing source code. Is there any plugin to do that? :1zhelp:

Hmm yes, this would be an interesting plugin, or you could put a content locker!

ardley216 said:

Hmm yes, this would be an interesting plugin, or you could put a content locker!

Click to expand...

It won't work, can be easily revealed by disabling JS or using CTRL + U. Users are so smart. I use Ajax to do this, in a landing page, but looking for a ready made plugin on WordPress.