PHP登录表单会话错误

所以我真的是PHP的新手，我正在尝试制作一个登录表单，当用户输入数据库中的用户名和密码时，它会将它们重新定位到proj.PHP，并显示"欢迎name"。我还没有添加该代码，因为到目前为止，当我使用正确的用户名和密码时，它会定位到login.php，但不会将用户重新定位到主页。任何帮助-非常感谢！我也很感激我可能遗漏了一些代码。。。到目前为止，我还没有发现任何有效的方法。

登录.php

//connection
$servername = "localhost";
$username = "root";
$password = "***";
$dbname = "login";
$conn = mysqli_connect($servername,$username,$password,$dbname);
if (!$conn) {die("connection failed; " . mysqli_connect_error());}


// Define $username and $password
$error=''; // Variable To Store Error Message
if (isset($_POST['submit'])) {
if (empty($_POST['dbusername']) || empty($_POST['dbpassword'])) {
$error = "Username or Password is invalid";
}
else
{
// Define $username and $password
$dbusername=$_POST['dbusername'];
$dbpassword=$_POST['dbpassword'];
// Create connection
$conn = mysqli_connect($servername, $username, $password, $dbname);
// Check connection
if (!$conn) {
    die("Connection failed: " . mysqli_connect_error());
}

$result = mysqli_query("SELECT dbusername FROM login WHERE dbusername='$dbusername' and dbpassword='$dbpassword'", $conn);
$count=mysqli_num_rows($result, $conn);
  $rows = mysqli_num_rows($query);
    if ($count == 1) {
        session_start();
        $_SESSION['dbusername']= $_POST('dbusername');
        header('Location: proj.php'); // Redirecting To Other Page
    } else {
        $error = "Username or Password is invalid";
    }
}
}
?>

项目.php

<div id="main>"
        <div id="login">
        <form class="navbar-form navbar-right" action="login.php" method="post" name="myForm" onsubmit="return validateForm()">
            <div class="form-group">
              <input type="text" placeholder="Username" class="form-control" name="username" id="name">
            </div>
            <div class="form-group">
              <input type="password" placeholder="Password" class="form-control" name="password" id="name">
            </div>
            <input type="submit" type=""name="submit" class="btn btn-success"></button>
          </form>
          <table border="0" cellpadding="10" cellspacing="1" width="500" align="center">

          <script>