无法用PHP DOM替换三个XML节点

Question

I am trying to change several xml node values, but I am able to change only two values...

$file = "../generavimui/word/document.xml";                                         

$fp = fopen($file, "rb") or die("nepavyko atidaryti document failo");
$str = fread($fp, filesize($file));
$xml = new DOMDocument();                                
$xml->formatOutput = true;
$xml->preserveWhiteSpace = false;
$xml->loadXML($str) or die("Error");

$root   = $xml->documentElement;
$fnode  = $root->childNodes->item(0);

$ori    = $fnode->childNodes->item(4);                      //1 paragrafas
$ori1    = $ori->childNodes->item(1);
$ori2   = $ori1->lastChild;

$ori0    = $fnode->childNodes->item(5);                     //2paragrafas
$ori3    = $ori0->childNodes->item(1);
$ori4   = $ori3->lastChild;

$wt     = $xml->createElement("w:t");
$wtText = $xml->createTextNode("Vardas: ".$vard.",   Pavardė: ".$pavard.",    Adresas: ".$adres.".");
$wt->appendChild($wtText);
$ori1->replaceChild($wt,$ori2);

$wt0     = $xml->createElement("w:t");
$wtText0 = $xml->createTextNode("Prekės pavadinimas: ".$pavadinimas.",  Kaina: ".$kaina."lt.");
$wt0->appendChild($wtText0);
$ori3->replaceChild($wt0,$ori4);
$xml->save("../generavimui/word/document.xml");

When I try to add third block of code then nothing happening... Any suggestions?