+3  A: 

Viewing the page's source code, I see:

<body onload="OnLoad();window.print();" onunload="OnUnload()">

It's the window.print(); you're interested in.

Although a matter of personal choice, I'm not a fan of web pages invoking system dialogs. It's that whole "don't take control of my computer" thing, like sites that maximize the browser, try to pop-up windows, etc. I'll call a link "Printer Friendly Version" rather than "Print this Page", assuming the user can figure out how to do File -> Print.

Bob Kaufman
+1 I don't really like that kind of intrusive javascript, remind me too much the time when javascript was a language to make pron ad based popup ...
RageZ
A: 

Add this to the bottom of a page, and the print dialog will pop up.

<script type="text/javascript">
window.print();
</script>
Palo Verde