php动态表导出数据出问题。求高手

代码如下：download.php的代码<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>课件下载</title>
<style type="text/css">body {
margin-left: 0px;
margin-top: 0px;
margin-right: 0px;
margin-bottom: 0px;
}
.STYLE1 {font-size: 12px}
.STYLE3 {font-size: 12px; font-weight: bold; }
.STYLE4 {
color: #03515d;
font-size: 12px;
}
a{
text-decoration:none;
}
</style>
</head>
<?php 
   $db_host = "localhost"; //MYSQL服务器名
$db_user = "root"; //MYSQL用户名
$db_pass = ""; //MYSQL用户对应密码
$db_name = "ta_db"; //指定本系统所用的数据库
$table_name = "ta_courseware"; //指定使用的数据表
//使用mysql_connect()函数对服务器进行连接，如果出错返回相应信息
$link = mysql_connect ( $db_host, $db_user, $db_pass ) or die ( "不能连接到服务器" . mysql_error () );
mysql_select_db ( $db_name, $link ); //选择相应的数据库，这里选择stu数据库$table_name="ta_courseware";                  //指定使用的数据表
mysql_query("SET NAMES UTF8");          //指定编码为UTF8
$sql = "select * from  $table_name ";
$result = mysql_query ( $sql ) or die ( "查询时出错" . mysql_error () ); // 发送SQL请求
    $i=1;
?>
<body>
<table width="100%" border="0" cellspacing="0" cellpadding="0">
  <tr>
    <td height="30" background="../tab/images/tab_05.gif"><table width="100%" border="0" cellspacing="0" cellpadding="0">
      <tr>
        <td width="12" height="30"><img src="../tab/images/tab_03.gif" width="12" height="30" /></td>
        <td><table width="100%" border="0" cellspacing="0" cellpadding="0">
          <tr>
            <td width="46%" valign="middle"><table width="100%" border="0" cellspacing="0" cellpadding="0">
              <tr>
                
                <td width="95%" class="STYLE1"><span class="STYLE3">你当前的位置</span>：[课件管理]-[课件下载]</td>
              </tr>
            </table>
            </td>
           
          </tr>
        </table></td>
        <td width="16"><img src="../tab/images/tab_07.gif" width="16" height="30" /></td>
      </tr>
    </table></td>
  </tr>
  <tr>
    <td><table width="100%" border="0" cellspacing="0" cellpadding="0">
      <tr>
        <td width="8" background="../tab/images/tab_12.gif"></td>
        
        <td><table width="100%" border="0" cellpadding="0" cellspacing="1" bgcolor="b5d6e6" >
          <tr>
            <td width="3%" height="22" background="../images/bg.gif" bgcolor="#FFFFFF"><div align="center"><span class="STYLE1">序号</span></div></td>
            <td width="12%" height="22" background="../images/bg.gif" bgcolor="#FFFFFF"><div align="center"><span class="STYLE1">ID</span></div></td>
            <td width="15%" height="22" background="../images/bg.gif" bgcolor="#FFFFFF"><div align="center"><span class="STYLE1">课件名称</span></div></td>
           
          
           <td width="20%" height="22" background="../images/bg.gif" bgcolor="#FFFFFF" class="STYLE1"><div align="center">基本操作</div></td>
            <td width="20%" height="22" background="../images/bg.gif" bgcolor="#FFFFFF" class="STYLE1"><div align="center">删除</div></td>
          </tr>
         <?
   
     while($row = mysql_fetch_array ( $result ))
    {
    ?> 
          <tr>
            
            <td height="20" bgcolor="#FFFFFF"><div align="center" class="STYLE1">
               <? echo $i++ ?>
            </div></td>
            <td height="20" bgcolor="#FFFFFF"><div align="center"><span class="STYLE1"> <? echo $row["ta_Id"]; ?></span></div></td>
            <td height="20" bgcolor="#FFFFFF"><div align="center"><span class="STYLE1"> <?=$row["ta_Name"]?> </span></div></td>
            
            
            <td height="20" bgcolor="#FFFFFF"><div align="center"><span class="STYLE4">
            <img src="../images/edt.gif" width="16" height="16" /><a href='downloaddo.php?FileName=<?=$row["ta_SrcFileName"]?>'>下载</a>
            </div></td>
            <td bgcolor="#FFFFFF"><div align="center"><span class="STYLE1"> <a href='delete.php?name=<?=$row["ta_SrcFileName"]?>'>删除</span></div></td>
          </tr>
    <?
  }
  
    ?>      
               
        </table></td>
        <td width="8" background="../tab/images/tab_15.gif">&nbsp;</td>
      </tr>
    </table></td>
  </tr>
  <tr>
    <td height="35" background="../tab/images/tab_19.gif"><table width="100%" border="0" cellspacing="0" cellpadding="0">
      <tr>
        <td width="12" height="35"><img src="../tab/images/tab_18.gif" width="12" height="35" /></td>
        <td><table width="100%" border="0" cellspacing="0" cellpadding="0">
          <tr>
          </tr>
        </table></td>
        <td width="16"><img src="../tab/images/tab_20.gif" width="16" height="35" /></td>
      </tr>
    </table></td>
  </tr>
</table>
</body>
</html>downloaddo.php代码：<?php
$filename=$_GET ["FileName"];
$newname ="upload/".iconv("utf-8","gb2312",$filename);
header('Content-Description: File Transfer');
header('Content-Type: application/octet-stream'); 
header("Content-Disposition: attachment; filename=".basename($newname)); 
header('Content-Transfer-Encoding: binary');
header('Expires: 0');
header('Cache-Control: must-revalidate, post-check=0, pre-check=0');
header('Pragma: public');
header('Content-Length: ' . filesize($newname));
ob_clean();
flush();
readfile($newname);
exit; 
?>错误提示：php