Request Help for reading a line of JS
<p>Can someone tell me what the ? means in the js below?  I did not line wrap the JS code as I did not want to inadvertently change the meaning...</p>

<pre><code>errMess = t.origStatus != undefined &amp;&amp; t.status != t.origStatus &amp;&amp; t.statuseffective == null ? errMess + t.systemname + ": Status effective date invalid.\n" : errMess;
</code></pre>

<p>I read this as:<br>
errMess =<br>
t.original status not equal to undefined AND<br>
t.status not equal to original status AND<br>
statuseffective equals null <strong>?</strong>  &lt;-- don't know what this means</p>
