Xml Problem

[Acs]

Hey! I am new to xml in php so I tried the php xml example from the simpleXML page

$xml = "<?xml version=\"1.0\" encoding=\"utf-8\" ?><teste></teste>";
$xmlstr = <<<XML
<?xml version='1.0' standalone='yes'?>
<movies>
<movie>
  <title>PHP: Behind the Parser</title>
  <characters>
   <character>
    <name>Ms. Coder</name>
    <actor>Onlivia Actora</actor>
   </character>
   <character>
    <name>Mr. Coder</name>
    <actor>El Act&#211;r</actor>
   </character>
  </characters>
  <plot>
   So, this language. It's like, a programming language. Or is it a
   scripting language? All is revealed in this thrilling horror spoof
   of a documentary.
  </plot>
  <great-lines>
   <line>PHP solves all my web problems</line>
  </great-lines>
  <rating type="thumbs">7</rating>
  <rating type="stars">5</rating>
</movie>
</movies>
XML;

$var = new SimpleXMLElement($xmlstr);
$var->movies->addChild("bla");
echo $var->asXML();

 

On the "$var->movies->addChild("bla");" I get this warning:

 

Warning: SimpleXMLElement::addChild() [function.SimpleXMLElement-addChild]: Cannot add child. Parent is not a permanent member of the XML tree

 

The movies element is there, why is this not working??

 

I am on winxp pro sp2 with php 5.2.5 on apache 2.0.55 (also using eAccelerator0952_5.2.5)