php提交表单的问题！急

给你一个我写的：<?php
if( count($_POST) > 0 )
{
  require_once("../connect.php");  $query = "select * from users where number='$number'";//检查新帐号是否已经存在
  $result = mysql_query($query);
  $rows = mysql_num_rows($result);
  if ($rows == 0)
     {
  $query = "insert into users(number, password, name, flag) values('$number', '$password', '$name', '$flag')";
  mysql_query($query);
      header("Location: list_admin.php");
      }
  else { header("Location: add_error.php");}
mysql_close($connect);
}
?>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312" />
<title>无标题文档</title>
<link href="../style.css" rel="stylesheet" type="text/css" />
<script language="JavaScript">
<!--
window.onload=function (){//页面加载完毕时执行
    var obj=document.form;
    obj.onsubmit=function(){//验证表单的函数
    var error=""
    if(obj.number.value=="")error+="●帐号不能为空!\n\n";
    if(obj.password.value=="")error+="●密码不能为空!\n\n";
    if(obj.name.value=="")error+="●姓名不能为空!\n\n";
    if(error!=""){alert("友情提示：\n\n"+error);return false;}
    else return true;
    }
}
//-->
</script>
</head><body>
<table width="60%" border="0" align="center" cellspacing="0">
  <tr>
    <td height="15">&nbsp;</td>
  </tr>
  <tr>
    <td><div align="center"><img src="../images/admin_add.gif" width="180" height="25" /></div></td>
  </tr>
  <tr>
    <td height="15">&nbsp;</td>
  </tr>
  <tr>
    <td><form id="form" name="form" method="post" action="<?php echo $PHP_SELF;?>">
      <table width="41%" border="0" align="center" cellspacing="0">
        <tr>
          <td class="td">帐号：</td>
          <td class="td"><label>
            <input name="number" type="text" id="number" size="20" maxlength="12" />
          </label></td>
        </tr>
        <tr>
          <td class="td">密码：</td>
          <td class="td"><label>
            <input name="password" type="text" id="password" size="20" maxlength="15" />
          </label></td>
        </tr>
        <tr>
          <td class="td">姓名：</td>
          <td class="td"><label>
            <input name="name" type="text" id="name" size="20" maxlength="8" />
          </label></td>
        </tr>
        <tr>
          <td><input name="flag" type="hidden" id="flag" value="1" /></td>
          <td>&nbsp;</td>
        </tr>
        <tr>
          <td colspan="2"><label>
            <div align="center">
              <input name="Submit" type="submit" class="button" value="添加" />
              </div>
          </label></td>
          </tr>
      </table>
        </form>
    </td>
  </tr>
</table>
</body>
</html>