為啥我的注冊網站空白的Orz

如題,php代碼如下,我已經把php.ini里面的extension=php_mssql.dll都打開了- -為啥還是空白
我用的是appserv 2.5.1
<?php
require('./configs/reg_conf.php');
function doesUsernameExist($name){
   $exit = FALSE;
   $result = @mssql_query("SELECT * FROM ACCOUNT_TBL WHERE account='$name'");
   if (mssql_num_rows($result) != 0){
       $exit = TRUE;
   }
   return $exit;
}

if(isset($_POST['submit'])){
   $user = preg_replace ("[^A-Za-z0-9]", "", $_POST['username']);
   $pass = preg_replace ("[^A-Za-z0-9]", "", $_POST['password']);
   if($_POST['username'] == ""){
       echo '<font color="red">Enter a user.</font><br /><br />';
   }
   else if($_POST['password'] == ""){
echo '<font color="red">Enter a password.</font><br /><br />';
   }
   else if ((strlen($_POST['username']) > 16) || (strlen($_POST['username']) < 3)){
echo '<font color="red">The user should be 3 to 16 characters.</font><br /><br />';
   }
   else if ((strlen($_POST['password']) > 16) || (strlen($_POST['password']) < 3)){
echo '<font color="red">The password should be 3 to 16 characters.</font><br /><br />';
   }
   else if($_POST['username'] != $user){
echo '<font color="red">User with invalid characters.</font><br /><br />';
   }
   else if($_POST['password'] != $pass){
echo '<font color="red">Password with invalid characters.</font><br /><br />';
   }
   else {
$pass = md5('nForceIsGay' . $pass);
            if(!doesUsernameExist($user)){
                $stmt = mssql_init('webCreateAcc', $link);
                mssql_bind($stmt, '@account', $user, SQLVARCHAR, false, false, 15);
                mssql_bind($stmt, '@password', $pass, SQLVARCHAR, false, false, 36);
                mssql_bind($stmt, '@birthday', $b, SQLVARCHAR, false, false, 120);
                mssql_bind($stmt, '@email', $mail, SQLVARCHAR, false, false, 120);
                mssql_execute($stmt) or die ("Something is wrong on the execution");
                mssql_free_statement($stmt);
echo '<font color="blue">注册成功.</font><br /><br />';
            }
            else {
echo '<font color="red">用户已经存在.</font><br /><br />';
            }
        }
mssql_close();
    }

echo '<form action="register.php" method="post">';
echo '用户名: <input type="text" name="username" /><br />';
echo '密码: <input type="password" name="password" /><br />';
echo '<input type="submit" name="submit" value="确定注册" />';
echo '</form>';

?>

因為登錄器我不會= =

+我的QQ我帮你