登录错误login.php

Question

使用php时出现错误问题：

  

解析错误：语法错误，意外的$ end in   第18行的C：\ xampp \ htdocs \ login.php

这是我的 login.php ：

if (isset ($_GET ['submit'])) {
    $username = $_POST['username'];
  $check_username = mysql_query ("SELECT * FROM users WHERE username='$username'");
  $numrows = mysql_num_rows ($username);
  if ($numrows != 1) {
    echo 'that User doesn\'t exist.';
}

?>
<h2>Login to your Account</h2>
<form action='login.php' method='POST'>
<input type='text' name='username' value='Username ...' onclick='value=""' /><p />
<input type='password' name='password' value='Password ...' onclick='value=""' /><p />
<input type='submit' name='submit' value='Login to my Accou`nt' />
</form>