更新复选框值从表单到数据库btu错误发生

Question

我在存储和更新复选框值时遇到问题。

PHP代码

<?php 
require ("****");
$id =$_REQUEST['id'];
$conn = mysql_connect('localhost', 'root', ''); 
mysql_select_db('registerforn');
$result = mysql_query("SELECT * FROM regi_user WHERE id  = '$id'");
$row = mysql_fetch_array($result);
extract($_POST);
if(isset($save)){
$skills=implode("," , $skills);
$sql=mysql_query("UPDATE regi_user SET emp_name ='$emp_name',email ='$email',gender ='$gender',interest='$interest' , skills='$skills' WHERE id = '$id'");
     $retval = mysql_query( $sql, $conn );
     header('location:display.php');
 }
 ?>

HTML代码

<tr><th>
    Option Subject</th>
 <th>
<?php 
$chkbox=$row['skills'];
$skills=explode("," , $chkbox);
?>
    <input <?php if(in_array("oops",$row)){echo "checked";}?> type="checkbox" class="myCheckBox"  name="skills[]" id="skills" value="oops">OOPS<br>   <!--class="myCheckBox"-->
    <input <?php if(in_array("pic",$row)){echo "checked";}?> type="checkbox" class="myCheckBox"   name="skills[]" id="skills" value="pic">Programin In C<br>
    <input <?php if(in_array("java",$row)){echo "checked";}?> type="checkbox" class="myCheckBox"  name="skills[]" id="skills" value ="java" >JAVA<br>
    <input <?php if(in_array("ds",$row)){echo "checked";}?> type="checkbox" class="myCheckBox"  name="skills[]" id="skills" value="ds">DS
    <div id="msg55"></div>
    <!--<div class="msg22"></div>class="myCheckBox"-->
 </th>
</tr>

这是我的更新页面。所以那个时间发生了问题 错误页面