xml - PHP change Value -

here script

    <?php  //open file , data $data = file_get_contents("import_produse.xml");  // tag replacements or whatever want $data = str_replace("cond","test", $data); $data = str_replace("condition","state", $data);  //save back: file_put_contents("imp.xml", $data);  ?> 

this script open .xml file , edit rows. need if found in lines price worth less $ 20 replace them 0.