Firstly, Google provide a nice site to craft your own.

That's okay for novices, but let's say we want to roll our own.

The search variable we are going to manipulate is called sitesearch. Leaving this value blank, means we're searching everything, adding your domain name and then it'll only search your site.

Source Code <form method="get" action="http://www.google.com/search"> <table border="0" cellpadding="0"> <tr> <td><input type="text" name="q" size="25" maxlength="255" value="" /> <input type="submit" value="Google Search" /></td> </tr> <tr><td align="center"><input type="checkbox" name="sitesearch" value="sikosis.com" checked /> only search Sikosis.com<br /></td> </tr> </table> </form>

---

Live Version

only search Sikosis.com