[jQuery] Select LIst with Jquery

[Danjojo]

I have some basic markup:

<img id="countryFlag" src="images/us.gif">
<select style="width: 100px;" onchange="javascript: alert('hello
world!');">
        <option value="0">Language</option>
        <option value="1">English</option>
        <option value="2">Japanese</option>
</select>

I have done some basic Jquery that changes or alters basic classes,
Id's, or element attributes.

But I am not sure how to use Jquery in a function manner yet.

How do I get the src for the flag image to change, id countryFlag,
when Japanese is selected?