Template:Showhide box

Usage
You need to include width=, header=, and content=. Fill in the information after the = signs. Header is what will be in the "always show" part of the box. Content will be the part that will have a button to be hidden. Width, header, and content are capitalisation senstive and must be all lowercase.

You can SUBST: this template so you can add style parameters afterwards. This is more advanced, and will clutter up a page with many SUBST:'d boxes quickly with code.