How to find targets for collapsible content scripts

If you want to change your document structure when using the script from the previous
section in this chapter, you need to find the parent/sibling path, in Internet Explorer and in
other browsers. If you’ve a good grasp of JavaScript, this should be simple; however, if you
don’t—or you just want to sanity-check your values—it’s simple to find out what an element’s
parent is, what it’s next sibling is, and various combinations thereof.
First, give your clickable element a unique id value:
<p><a id="linkToggler" href="#" title="Toggle section"
å onclick="toggle(this); return false;">Toggle div 1!</a></p>
Elsewhere within the web page, add the following script:
<script type="text/javascript">
//<![CDATA[
alert(document.getElementById("linkToggler").nodeName);
//]]>
</script>
Before .nodeName, add whatever combination of .parentNode and .nextSibling you
like—here’s an example:
<script type="text/javascript">
//<![CDATA[
alert(document.getElementById("linkToggler").parentNode.
ånextSibling.nextSibling.nodeName);
//]]>
</script>
When you load the web page in a browser, an alert message will be displayed. This will
detail what the target element is, based on the path defined in the previous code block.