firstChild Fails

JavaScript
1 
<li id="feed_1">
      <a id="feed_1_1" href="">
</li>

var feed_1 = document.getElementById('feed_1');
	
if (feed_1)
{
	alert(feed_1.firstChild.id);
}
2

The firstChild will be a newline character. One way to get the first HTML child element would be:

alert( feed_1.getElementsByTagName( '*' )[ 0 ] );

Also avoid global variable names that clash with IDs