Can someone explain the following javascript code?
<p>In addition to the explanation, what does the $ mean in javascript?  Here is the code:</p>

<pre><code>var ZebraTable = {
    bgcolor: '',
    classname: '',
    stripe: function(el) {
     if (!$(el)) return;
     var rows = $(el).getElementsByTagName('tr');
 for (var i=1,len=rows.length;i&lt;len;i++) {
  if (i % 2 == 0) rows[i].className = 'alt';
  Event.add(rows[i],'mouseover',function() { 
ZebraTable.mouseover(this); });
 Event.add(rows[i],'mouseout',function() { ZebraTable.mouseout(this); });
 }
},
mouseover: function(row) {
 this.bgcolor = row.style.backgroundColor;
 this.classname = row.className;
 addClassName(row,'over');
},
mouseout: function(row) {
 removeClassName(row,'over');
 addClassName(row,this.classname);
 row.style.backgroundColor = this.bgcolor;
}
}

window.onload = function() {
ZebraTable.stripe('mytable');
}
</code></pre>

<p>Here is a link to where I got the code and you can view a demo on the page.  It does not appear to be using any framework.  I was actually going through a JQuery tutorial that took this code and used JQuery on it to do the table striping.  Here is the link:</p>

<p><a href="http://v3.thewatchmakerproject.com/journal/309/stripe-your-tables-the-oo-way" rel="nofollow">http://v3.thewatchmakerproject.com/journal/309/stripe-your-tables-the-oo-way</a></p>
