getElementById id does not exist
<p>I have run into a problem with getElementById again.. I never quite understood the behaviour of this method, as simple as it should be, it often doesn't work for me.</p>

<p>What I have now is a HTML page that contains:</p>

<pre><code>&lt;div id="vraag"&gt;
    ha
&lt;/div&gt;

&lt;div id="antwoorden"&gt;

&lt;/div&gt;
&lt;div id="controls"&gt;
    &lt;form name="controlform"&gt;
        &lt;input type="button" name="back" disabled value="&lt;" onClick="goBack();" /&gt;
        &lt;input type="button" name="forth" value="&gt;" onClick="goForth();" /&gt;
    &lt;/form&gt;
&lt;/div&gt;
</code></pre>

<p>I have attached a javascript file that does several (working) things, among which is this:</p>

<pre><code>document.getElementById['vraag'].innerHTML = 'ho';
</code></pre>

<p>However, when I click the button that calls this, the firefox error console says:
<code>Error: document.getElementById.vraag is undefined</code></p>

<p>Sadly, the only think I can think of is.. It simply is! I have used this method in very similar environments and that still works, so I can't for the life of me figure out why this doesn't work..</p>
