Login form HTML

function loginForm($action, $username = "", $password = "")
{
  if (empty($username)) {
    $username = "Username";
  }
  if (empty($password)) {
    $password = "password";
  }
  return '<form action="'.$action.'" method="POST">
    <input type="text" name="username" placeholder="'.$username.'"/>
    <input type="password" name="password" placeholder="'.$password.'"/>
    <input type="submit" value="Login" />
  </form>';
}