Let's see how to clone an element node with cloneNode().
Clone a Node with cloneNode() Method
The cloneNode() method creates a copy of a specified node.
The cloneNode() method has a parameter (true or false). This parameter indicates if the cloned node should include all attributes and child nodes of the original node.
Example: clone the first <book> node and appends it to the root node of the document:
oldNode = xmlDoc.getElementsByTagName('book')[0];
newNode = oldNode.cloneNode(true);
xmlDoc.documentElement.appendChild(newNode);