HTTP404未找到

点击确定按钮时出现找不到网页;代码如下
CODE{
<?php
if(isset($_POST['Submit'])){
   require_once('connect.inc');
   require_once('function.php');
   $db = new mysql();
   $db->connect($mydbhost, $mydbuser, $mydbpw, $mydbname,$mydbcharset);
   
   
  if($_POST['password2'] !=$_POST['password'] ){
  ?>
     <script language="javascript">
<!--
alert("您两次输入的密码不匹配!");
//-->
</script>
<?php       
}
         
   $sql = "insert into member values(null,'".html($_POST['name'])."','".html($_POST['password'])."')";
  $query=$db->query($sql);
  if($query)
  {
  header("location:main.php");
  }
}

?>

<!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=hz-gb-2312" />
<title>注册</title>
<link href="style.css" rel="stylesheet" type="text/css" />

</head>

<body>
<script language="javascript">
function check(){
if(document.form1.name.value == ''){
  alert('姓名不能为空.');document.form1.name.select();
  return false;
  }
if(document.form1.password.value == ''){
  alert('密码不能为空.');document.form1.name.select();
  return false;
  }
return true;
}
</script>
<form id="form1" name="form1" method="post" action="" onSubmit="return check()">
  <table width="250" border="1" class="tableboder" align="center" cellpadding="1" cellspacing="1">
    <tr>
      <td height="20" class="header" colspan="2">网络名片注册</td>
    </tr>
    <tr>
      <td height="20">姓名:</td>
      <td height="20"><input name="name" type="text" size="15" maxlength="20" /></td>
    </tr>
    <tr>
      <td height="20">密码:</td>
      <td height="20"><input name="password" type="password" size="15" maxlength="20" /></td>
    </tr>
    <tr>
      <td height="20">确认密码:</td>
      <td height="20"><input name="password2" type="password" size="15" maxlength="20" /></td>
    </tr>
    <tr>
      <td height="20" colspan="2"><div align="center">
        <input type="reset" name="Submit2" value="重置" />   
        <input type="submit" name="Submit" value="提交" />
      </div></td>
    </tr>
  </table>
</form>

</body>
</html>
}