Problem running "Practical Prototype ..." example

I tried running the example in the text around Figures 4.1 , 4.2. I'm
running WinXP-Pro/SP3, Firefox 3.6.2, Firebug 1.5.3. All the details
are in the following Command Window results. It's pretty obvious that
"new" is not a regularly recognized Windows command, but I don't know
whether the author was running Unix, Linux, Mac OS or something else.
BTW, I think this book is a great tutorial.

Thanks in Advance,
Richard

K:\>cd K:\_Projects\Ruby\_Rails_Apps\__PracticalPrototypeExamples

K:\_Projects\Ruby\_Rails_Apps\__PracticalPrototypeExamples>JS_01.html
[The Figure 4.1 window came up in Firefox 3.6.2, including the Firebug
pane]

K:\_Projects\Ruby\_Rails_Apps\__PracticalPrototypeExamples>new
ajax.request('ajax.js', {method: 'get'})
'new' is not recognized as an internal or external command,
operable program or batch file.

K:\_Projects\Ruby\_Rails_Apps\__PracticalPrototypeExamples>type
JS_01.html
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
       "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
<head>
  <meta http-equiv="content-type" content="text/html;charset=UTF-8" />
  <script type="text/JavaScript" src="prototype.js"></script>
  <title>JS_01</title>
</head>

<body>
    <h1>Blank Page</h1>

</body>
</html>

K:\_Projects\Ruby\_Rails_Apps\__PracticalPrototypeExamples>type
ajax.js
alert("Hello from Ajax.js");

K:\_Projects\Ruby\_Rails_Apps\__PracticalPrototypeExamples>

Problem solved somewhat: I was supposed to paste the "new ..." code in
Firebug:Console, not a Command Window. I've still got a problem,
but I'll post it on a new thread.