关于上传问题，高手们来帮忙下啦

Question

$guestbook = new DomDocument(); //创建一个新的 DOM对象
$guestbook->load('guestbook.xml'); //读取 XML数据
$threads = $guestbook->documentElement; //获得 XML结构的根
//创建一个新 thread节点
$thread = $guestbook->createElement('thread');
$threads->appendChild($thread);
//在新的 thread节点上创建 title标签
$title = $guestbook->createElement('title');
$title->appendChild($guestbook->createTextNode($_POST['title']));
$thread->appendChild($title);
//在新的 thread节点上创建 author标签
$author = $guestbook->createElement('author');
$author->appendChild($guestbook->createTextNode($_POST['author']));
$thread->appendChild($author);
//在新的 thread节点上创建 content标签
$content = $guestbook->createElement('content');
$content->appendChild($guestbook->createTextNode($_POST['content']));
$thread->appendChild($content);
//=========================================================
$threads->appendChild($guestbook->createTextNode("\n"));//这样来添加换行
//=========================================================
//将 XML数据写入文件
$fp = fopen("guestbook.xml", "w");
if(fwrite($fp, $guestbook->saveXML()))
{
//fwrite($fp,"\r\n");
echo "成功";
echo " <script language='Javascript'>
      parent.location.reload();
        </script>";
}
else
echo "留言提交失败";
fclose($fp); 做了个留言板，php操作XML本地测试成功，上传到服务器就出错，显示留言内容那部分出错Warning: simplexml_load_file() [function.simplexml-load-file]: I/O warning : failed to load external entity "guestbook.xml" in E:\www\14598\3.php on line 4 Notice: Trying to get property of non-object in E:\www\14598\3.php on line 5 Warning: Invalid argument supplied for foreach() in E:\www\14598\3.php on line 5 请问是什么问题呢？该怎么修改？ 
有guestbook.xml这个文件 
3.php这行就是$guestbook=simplexml_load_file('guestbook.xml');和下面行 
foreach($guestbook->thread as $th)

Answer 1

是什么服务器？如果是 linux 服务器的话chmod 755 guestbook.xml

Answer 2

////////////////////////////////////////////////////////* 取得当前FILE所在的根目录 */define ('GUESTBOOK', "dirname(__FILE__)/gusetbook.xml");///////////////////////////////////////////////////////$guestbook = new DomDocument(); //创建一个新的 DOM对象
$guestbook->load(GUESTBOOK); //读取 XML数据
$threads = $guestbook->documentElement; //获得 XML结构的根
//创建一个新 thread节点
$thread = $guestbook->createElement('thread');
$threads->appendChild($thread);
//在新的 thread节点上创建 title标签
$title = $guestbook->createElement('title');
$title->appendChild($guestbook->createTextNode($_POST['title']));
$thread->appendChild($title);
//在新的 thread节点上创建 author标签
$author = $guestbook->createElement('author');
$author->appendChild($guestbook->createTextNode($_POST['author']));
$thread->appendChild($author);
//在新的 thread节点上创建 content标签
$content = $guestbook->createElement('content');
$content->appendChild($guestbook->createTextNode($_POST['content']));
$thread->appendChild($content);
//=========================================================
$threads->appendChild($guestbook->createTextNode("\n"));//这样来添加换行
//=========================================================
//将 XML数据写入文件
$fp = fopen("guestbook.xml", "w");
if(fwrite($fp, $guestbook->saveXML()))
{
//fwrite($fp,"\r\n");
echo "成功";
echo " <script language='Javascript'>
      parent.location.reload();
        </script>";
}
else
echo "留言提交失败";
fclose($fp); 

Answer 3

if(!isset($_SERVER['DOCUMENT_ROOT'])) 
{    
  if(isset($_SERVER['SCRIPT_FILENAME'])) 
  { 
  $_SERVER['DOCUMENT_ROOT'] = str_replace( '\\', '/', substr($_SERVER['SCRIPT_FILENAME'], 0, 0-strlen($_SERVER['PHP_SELF']))); 
  } 
} 
if(!isset($_SERVER['DOCUMENT_ROOT'])) 
{ 
  if(isset($_SERVER['PATH_TRANSLATED'])) 
  { 
  $_SERVER['DOCUMENT_ROOT'] = str_replace( '\\', '/', substr(str_replace('\\\\', '\\', $_SERVER['PATH_TRANSLATED']), 0, 0-strlen($_SERVER['PHP_SELF']))); 
  } 
} 
   function request_uri() {
    if (isset($_SERVER['REQUEST_URI']))     {
          $uri = $_SERVER['REQUEST_URI'];
  }
else{
   if (isset($_SERVER['argv'])){
     $uri = $_SERVER['PHP_SELF'] .'?'. $_SERVER['argv'][0];
}
else {
 $uri = $_SERVER['PHP_SELF'] .'?'. $_SERVER['QUERY_STRING'];
}
}
 return $uri;
   }
------------------------------------------------------------------
路径= $_SERVER['DOCUMENT_ROOT'].dirname(request_uri())
url= "http://".$_SERVER ['HTTP_HOST'].dirname(request_uri())我不知道是否对你有帮助，我自己的上传文件页是这么写的，本地和远程的虚拟主机都能通过