Understanding javascript closure
<pre><code>function makeHelpCallback(help) {
  return function() {
    showHelp(help);
  };

//array elements here

  for (var i = 0; i &lt; helpText.length; i++) {
    var item = helpText[i];
    document.getElementById(item.id).onfocus = makeHelpCallback(item.help);
}
</code></pre>

<p>I am having trouble understanding the last line. I have never seen the equal sign used in that way,</p>
