Why can I set the text in a textbox but I can't clear it?
<p>I have this written in a certain Javascript function.</p>

<pre><code>document.getElementById("textbox").innerHTML = "some text";
</code></pre>

<p>This does what you'd expect. However, if I slightly modify it to try to clear the text box like this</p>

<pre><code>document.getElementById("textbox").innerHTML = "";
</code></pre>

<p>It doesn't work. Why?</p>
