Spoiler will be particularly good for the Learning Series... wonder how good it works with code...

lets see here... Appears the code tags works best in the spoiler box.

Spoiler with HTML(Post Prep)
Warning, Spoiler:

<fieldset style='background:#f0f0f0;border-style:solid;border-width:2'><pre><font face='Courier New' size=2 color=#9932CC><font color=#0000FF>break</font> <font color=#0000FF>on</font>
<font color=#0000FF>if</font> <font color=#000000><b>@error</b></font>
? <font color=#000000><b>@error</b></font>
? <font color=#000000><b>@serror</b></font>
<font color=#0000FF>endif</font></font></pre></fieldset>


Spoiler with text
Warning, Spoiler:

break on
if @error
? @error
? @serror
endif


Spoiler with code tags
Warning, Spoiler:

 Code:
break on
if @error
  ? @error
  ? @serror
endif