Conditional Plugin for additional.css

[Jacob_ITAPros]

I'm attempting to create a plugin that will check certain conditions before appending css to additional.css. Here is what I have for a plugin at hook: cache_templates.

if in_array($foruminfo['forumid'] == array(2,7)) {
  $sp_css = array
  (
   ".forumbit_post .foruminfo {;",
   " width: 57%;",
   " min-width: 30%;",
   " float: {vb:stylevar left};",
   " clear: {vb:stylevar right};",
   " min-height: 85px;",
   "}"
   )

  foreach ($sp_css as $value) {
  echo $value;
  }


vB_Template::preRegister('additional.css',array('sp_css' => $sp_css))

If there is a way that I can have the array in this plugin display each element I think this would work. The goal in this particular experiment would be, if specfic forum ID's are matched, add these lines to additional.css. Obviously what I have here isn't working.

I'm completely new to PHP and vBulletin so be nice. :-)