Unexpected alert with message "undefined" after successfully calling simple function with arguments
<p>Can anyone tell me why the following code produces the alert box that I expect (RyeTofuRye), but then produces a second alert box with the message "undefined?"  At least that's what it's doing in the latest FireFox on my Windows 7 machine.</p>

<pre><code>function makeSandwich(bread, meat) {
alert(bread + meat + bread);
}
var mySandwich = makeSandwich('Rye', 'Tofu');
alert(mySandwich);
</code></pre>
