Creating a Back Button in Joomla

So, I wanted to create a back button, as one of my articles did not provide an adequate link to the previous item. I found this article which describes a simple a tag which calls javascript. Heres the example:

Go back

for none javascript browsers he proposes this:

Go back

I then created a module called "Back Button" with this link, and made it appear only on the pages I wanted. It nearly worked but unfortunately I couldn't get the WYSYWIG editor to let me put the javascript entry in, it always wiped it out!!

Ended up going into the database and pasting it in myself! If someone could please let me know for next time how I get TINYMCE to let me put this code in to a customHTML module in Joomla!!

after comingback to this some time later, i accidentally saved it and it deleted the code! But now, if I want code I install flexi custom code, which lets you add javascript, php etc. to modules!