PHP:登录无法将文件托管到 Web 服务器.在本地主机上效果很好

Question

我的登录模式使用方法post并将变量发送到另一个文件(在不同的文件夹中(，该文件在我的本地主机上运行良好，但在托管时会引发以下错误：

HTTP 500 错误 这很奇怪...网站无法显示此页面

如果我重新加载此页面，我将被重定向回主页而无需登录(http：//.../index.php？登录 = 错误 3(。

登录文件： <</p>

form class="modal-contents animate" action="Fon/LogInFile.php" method="POST">
        <span onclick="document.getElementById('id').style.display='none'" class="closes" title="Close Modal">&times;</span>
        <div class="container1">
      <h2> Log In</h2>
          <tr><b> Email</b>
          <input type="text" placeholder="email" name="username" required></td></tr> <br>
          <tr style=""><td ><b>Password</b>
              <input type="password" placeholder="Enter Password" id="Pass" name="pswdd"; required></td></tr>
             <tr> <span class="psw">Forgot <a href="#"> password?</a></span></tr> <br>
      <tr><td><button type="submit" id= "LogInBut">Login</button></td></tr> 
        <tr><td><button type="button" onclick="document.getElementById('id02').style.display='none'" id="CancelBut">Cancel</button> </td></tr>
      </td></tr><input type="checkbox" checked="checked"> Remember me</td></tr>

fon/logInFile.php ：

if ($_SERVER["REQUEST_METHOD"]=="POST") {
include '../databaseconnection.php';    
    $username = mysqli_real_escape_string($link, $_POST['username']);
    $password = mysqli_real_escape_string($link, $_POST['pswdd']);
            //Error Handlers 
                    $_SESSION['user']=$username;
                    $_SESSION['password']=$password;
        header("Location: ../index.php?loginss=successful");
                    exit();
                }
else{
        header("Location: ../index.php?Loginn=error3");
        exit();
}
}

Answer 1

尝试

echo $_SERVER['REQUEST_METHOD'] == 'POST'; // To check the value
echo isset($_POST["submit"]) 
if ($_SERVER['REQUEST_METHOD'] == 'POST')
include '../databaseconnection.php';    
    $username = mysqli_real_escape_string($link, $_POST['username']);
    $password = mysqli_real_escape_string($link, $_POST['pswdd']);
            //Error Handlers 
                    $_SESSION['user']=$username;
                    $_SESSION['password']=$password;
        //header("Location: ../index.php?loginss=successful");
                  //  exit();
                }
else{
        //header("Location: ../index.php?Loginn=error3");
        //exit();
}
}