What is "i" in "function(i)" in the following JavaScript?
<p>In the following code there is "function(i)", but "i" hasn't been declared anywhere previous to this statement.</p>

<pre><code>ul.css({width: 10, overflow: 'visible'}).retarder(100, function(i){
   i.css('visibility',  'visible').animate(
      {width: ul[0].wid,left:-50},
      {duration: 500, complete : function(){
         ul.css('overflow',  'visible');
      }}
   );
});
</code></pre>

<p>It looks like it could be similar to a c++ "this" statement.  Is that correct at all?</p>
