Create XML without error using PHP arrays

Creating XML dynamically using php is quite simple . DOMDocument can be used for creating such xml file from arrays.
Check out following PHP code folr dynamic creation and output it in browser

$books = array(
 array (
  id => 1,
  author => "Someone",
  name => "Professional PHP"
   ),
 array (
  id => 2,
  author => "Nicholas C",
  name => "Professional Ajax"
   ),
 array (
  id => 3,
  author => "Joe Williams",
  name => "Beginning PHP"
  )
 );

$dom = new DomDocument(); 
$dom->formatOutput = true;

$root = $dom->createElement( "books" );
$dom->appendChild( $root );

foreach( $books as $book )
{
$bn = $dom->createElement( "book" );
 $bn->setAttribute( 'id', $book['id'] );

 $author = $dom->createElement( "author" );
 $author->appendChild( $dom->createTextNode( $book['author'] ) );
 $bn->appendChild( $author );

 $name = $dom->createElement( "name" );
 $name->appendChild( $dom->createTextNode( $book['name'] ) );
 $bn->appendChild( $name );
 $root->appendChild( $bn ); 
}
//output the xml in browser
header( "Content-type: text/xml" );
echo $dom->saveXML();

//or you can save the xml in file by doing the following
$dom->save("/somedirname/somefile.xml");
?>