Google -, .
<form method="get" action="http://www.google.com/search">
<label for="q">Search:</label>
<input id="q" name="q" size="20" maxlength="255" value="" type="text"/>
<input name="domains" value="http://www.mydomain.com/" type="hidden"/>
<input name="sitesearch" value="http://www.mydomain.com/" checked="checked" id="mysite" type="radio"/>
<label for="mysite">Just this site</label>
<input name="sitesearch" value="" id="www" type="radio"/>
<label for="www">WWW</label>
<input name="btnG" value="Go" type="submit"/>
</form>