How to create a custom callback
<p>I have a function that done some asynch operations :</p>

<pre><code>function funcAsynch() {
    // asynch operations
}
</code></pre>

<p>well, I'd like calling this function, and declare a callback to execute when all asynch operations are finished.</p>

<p>Somethings like </p>

<pre><code>customCallback(funcAsynch(), function () { 
    alert("all asynch operations are finished") 
});
</code></pre>

<p>how can I do it?</p>
