DOMNode appendChild(DOMNode newnode);
This functions appends a child to an existing list of children or creates a new list of children. The child can be created with e.g. DOMDocument->createElement(), DOMDocument->createTextNode() etc. or simply by using any other node.
Raised if this node is readonly or if the previous parent of the node being inserted is readonly.
Raised if this node is of a type that does not allow children of the type of the newnode node, or if the node to append is one of this node's ancestors or this node itself.
Raised if newnode was created from a different document than the one that created this node.
The following example will add a new element node to a fresh document.
$doc = new DOMDocument;
$node = $doc->createElement("para");
$newnode = $doc->appendChild($node);