Online PHP editor | output for aVfl7

<?php $domDoc = new DOMDocument; $domDoc->preserveWhiteSpace=false; $domDoc->loadXML(<<<XML <?xml version="1.0"?> <CONFIG> <APP-ID>166533e56</APP-ID> </CONFIG> XML ); $rootNode = $domDoc->documentElement; $config_root = $rootNode->getElementsByTagName("CONFIG"); $rootElt = $domDoc->createElement('USER-ID'); $subNode = $rootNode->appendChild($rootElt); $textNode = $domDoc->createTextNode('333265332f'); $subNode->appendChild($textNode); $rootElt = $domDoc->createElement('USER'); $sub2Node = $rootNode->appendChild($rootElt\n); $textNode = $domDoc->createTextNode('John'); $sub2Node->appendChild($textNode); $domDoc->formatOutput = true; //$domDoc->save('config.xml'); echo $domDoc->saveXML();