DOMDocument rimozione tag

[frangetta83]

Ciao!
devo rimovere l'andare a capo in un file xml, in particolare
devo sostituire il tag <text:line-break/> con un trattino, solo per le righe dentro il tag contenitore <text:index-body>
Questo è il mio codice:

<text:index-body>          <text:p text:style-name="P9">AAAA            <text:tab/>5</text:p>          <text:p text:style-name="P9">            <text:s/>BBB            <text:line-break/>bb1            <text:tab/>6</text:p>          <text:p text:style-name="P9">            <text:s/>CCC            <text:line-break/>cc1            <text:tab/>6</text:p>          <text:p text:style-name="P9"><text:index-body/>

$xml=new DOMDocument();$xml->load($_tmp."/content.xml");
$xp= new DOMXPath($xml);    $xquery = "/office:document-content/descendant-or-self::text:index-body";$xpic_art= $xp->query($xquery);for ($k=0; $k<$xpic_art->length; $k++) {    $s=$xpic_art->item($k);            $xpic5=$xp->query(".//text:line-break", $s);            if($xpic5->length >0){            $p=$xpic5->item(0);            $p->parentNode->replaceChild('', $p);         }}
    $content=$xml->saveXML(); 

dove sbaglio?