Question

I am new to HTML DOM operations. I failed even for simple examples.

Here are my codes:

<h1>head 1</h1>
<h2>head 2</h2>
<script type="text/javascript">
var h1 = document.getElementsByTagName('h1');
alert("tagName : "+h1.getTagName());
h1.parentNode.removeChild(h1);
</script>
<h3>head 3</h3>

The above codes even don’t pop out any “alert”.

I also tried:

alert("nodeType: "+h1.nodeType);
alert("nodeName: "+h1.nodeName);
alert("nodeValue: "+h1.nodeValue);
alert("tagName: "+h1.tagName);

However, they all response undefined.

Answer 1

This site is really useful.
http://www.w3schools.com/jsref/dom_obj_node.asp

Once you get a grasp of it, be sure to use jquery or some other library for working with dom (makes life easier):
http://jquery.com/

<h1>head 1</h1>
<h2>head 2</h2>
<script type="text/javascript">
var h1 = document.getElementsByTagName('h1')[0];
alert("tagName : "+h1.localName);
h1.parentNode.removeChild(h1);
</script>
<h3>head 3</h3>