JavaScript colon operator
<p>I am trying to learn JavaScript. After reading this page: <a href="http://stackoverflow.com/questions/418799/what-does-do-in-javascript">What does &#39;:&#39; do in JavaScript?</a></p>

<p>I tried to replace</p>

<pre><code>var store = new dojo.data.ItemFileReadStore({
         url: "countries.json"
 });
</code></pre>

<p>with </p>

<pre><code>var store = new dojo.data.ItemFileReadStore();
        store.url = "countries.json";
</code></pre>

<p>It does not work. Can any one please point out the mistake, or explain the correct use of the  Colon operator?.
Thanks.</p>
