php写xml文件问题

<?phpinclude("conn.php");include("crop.php");mysql_select_db('hdm0910283_db', $lnk) or die ('Can\'t use hdm0910283_db : ' . mysql_error());mysql_query("SET NAMES gbk");	$sql="select * from video";$query=mysql_query($sql);$str="<thumbnails>";while ($row = mysql_fetch_array($query)) {	//echo $row[imgname];	$imageurl="../workshow/images/".$row[imgname];    cutphoto("$imageurl","$imageurl",200,113);	$str=$str."<thumbnail filename=\"".$row[imgname]."\" label=\"".$row[title]."\" url=\"".$row[url]. "\"/>";	//echo $row[imgname];}header("content-type:text/html; charset=utf-8");    //指定PHP使用UTF-8编码$xml = simplexml_load_file("../workshow/xml/thumbnails.xml");        //读取xml文件$str = $xml->asXML();                              //标准化$xml$fp = fopen("../workshow/xml/thumbnails.xml", "w");                      //新建xml文件fputs($fp, $str);                                     //写入-------xml文件fclose($fp);?>

<?xml version="1.0"?><thumbnails><thumbnail filename="136421249467911.jpg" label="&#x94C1;&#x519B;-&#x7EAA;&#x5FF5;&#x957F;&#x6625;&#x51C0;&#x6708;&#x9AD8;&#x65B0;&#x533A;&#x57CE;&#x5E02;&#x7BA1;&#x7406;&#x884C;&#x653F;&#x6267;&#x6CD5;&#x5C40;&#x6210;&#x7ACB;" url="http://v.youku.com/v_show/id_XNTI5NzU4MzEy.html"/><thumbnail filename="136421346392337.jpg" label="&#x90A3;&#x4E00;&#x5E74; &#x8FD9;&#x4E00;&#x5E74;-&#x540C;&#x5B66;&#x4F1A;&#x7EAA;&#x5FF5;" url="http://v.youku.com/v_show/id_XNTI5NjEwMzMy.html"/><thumbnail filename="136421349294580.jpg" label="&#x677E;&#x539F;&#x7CAE;&#x98DF;&#x96C6;&#x56E2;&#x6709;&#x9650;&#x516C;&#x53F8;" url="http://v.youku.com/v_show/id_XNTI5Njk2MzQ0.html"/><thumbnail filename="136421354756516.jpg" label="&#x751F;&#x6001; &#x9B45;&#x529B; &#x548C;&#x8C10; &#x957F;&#x767D;&#x5C71;" url="http://v.youku.com/v_show/id_XNTI5Njg1OTEy.html"/><thumbnail filename="136421359617912.jpg" label="&#x5357;&#x90E1;&#x6C34;&#x4E91;&#x5929;3&#x53F7;" url="http://v.youku.com/v_show/id_XNTI5NjcyMDM2.html"/><thumbnail filename="136421362461256.jpg" label="&#x5409;&#x6797;&#x7701;&#x677E;&#x539F;&#x519C;&#x4E1A;&#x9AD8;&#x65B0;&#x6280;&#x672F;&#x5F00;&#x53D1;&#x533A;" url="http://v.youku.com/v_show/id_XNTI5NjAwNzQw.html"/><thumbnail filename="136421365264950.jpg" label="&#x957F;&#x6625;&#x5174;&#x9686;&#x7EFC;&#x5408;&#x4FDD;&#x7A0E;&#x533A;" url="http://v.youku.com/v_show/id_XNTI5NTg4MDI0.html"/></thumbnails>