Getting a NaN error when when calling a setTimeout
<p>I am trying to use a setTimeout function that calls itself and is broken by a counter. However, I keep gettng a NaN error. Can someone help me?</p>

<pre><code>&lt;script language="javascript"&gt;
    function Tests() {
        this.i = 0;
    }


    Tests.prototype.increment_test = function () {
        if (this.i &gt; 2) {
            return;
        }
        alert(this.i);
        this.i++;

        setTimeout(this.increment_test, 30);
    }

    ta = new Tests();
    ta.increment_test();
&lt;/script&gt;
</code></pre>
