"In Stock" code

I've been looking for this for a few hours - where is the snippet of code that is used to display “In Stock” and “out of stock”? I've tried looking in design mode and still can't find it!

just to be clear, I don't just want to modify the CSS or language file.

Any help is greatly appreciated.

have a look in skins//customer/common_templates/product_data.tpl

Thanks a lot for this :)