Need an explanation for this javascript code
<p>I started learning javascript last week, I saw this code yesterday and I did some researches about it, but now I can't figure what it does</p>

<pre><code>var y=document.forms['post'];
var x=y.message.value;
x=x.replace(/&lt;/gi,'(').replace(/\&lt;/gi,'(');
y.message.value=x;
</code></pre>
