How to enter Javascript into a wiki page?

How can I, as the wiki admin, enter scripting (Javascript) into a Sharepoint wiki page?

I would like to enter a title and, when clicking on that, having displayed under it a small explanation. I usually have done that with javascript, any other idea?

Solution

Assuming you're the administrator of the wiki and are willing display this on mouseover instead of on click, you don't need javascript at all -- you can use straight CSS. Here's an example of the styles and markup:

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN"
  "http://www.w3.org/TR/html4/strict.dtd">
<html>
<head>
  <title>Test</title>
  <style type="text/css">
    h1 { padding-bottom: .5em; position: relative; }
    h1 span { font-weight: normal; font-size: small; position: absolute; bottom: 0; display: none; }
    h1:hover span { display: block; }
  </style>
</head>
<body>
  <h1>Here is the title!
    <span>Here is a little explanation</span>
  </h1>
  <p>Here is some page content</p>
</body>
</html>

With some more involved styles, your tooltip box can look as nice as you'd like.