Adding a google search box?

How do I and am i allowed to add a google search box to my page, so users can search google via our website.

Thanks :)

HTML Code:

---

<form method="get" action="http://www.google.com/search">

<input type="text"  name="q" size="31"
 maxlength="255" value="" />
<input type="submit" value="Google Search" /> <br />

</form>

---

That's it, I'm surprised how little there is to it. Tested it and it works fine.