Variable visibility in blocks

Hello there, i have a quite strange behaviour in my latte.

This latte file should show an extra <script> block if there are errors in the form processing. As you can see i define the $errors as a “global” to the latte file.

Later I want to change its value if an error comes up and show the div accordingly. The problem is that the $errors variable in the scripts block always validates as in the definition {var $errors = 0}.

Any ideas what am i doing wrong?

<?php
{layout "../@login.latte"}
{var $errors = 0}
{block content}
<section class="container">
	<section class="login-form">
		{form signInForm}
			<div n:if="$form->ownErrors" n:foreach="$form->ownErrors as $error" class="alert alert-danger" style="margin-top: 0px"><span class="glyphicon glyphicon-remove"></span> {$error}</div>
			{php
				if ($form->ownErrors) {
					$errors = 1;
				} else {
					$errors = 0;
				};
			}
			<img src="{$basePath}/images/logo.png" class="img-responsive center-block" alt="" />

			<input n:name="username" placeholder="Přihlašovací jmeno" required class="form-control input-lg" />
			<input n:name="password" type="password" placeholder="Heslo" required class="form-control input-lg" />

			<button type="submit" name="send" class="btn btn-lg btn-block btn-primary">Přihlásit</button>
		{/form}
	</section>

</section>
{/block}
{block scripts}
	{include #parent}
	<script n:if="$errors == 1">
		$(function() {
  			$(".login-form").effect("shake");
		});
	</script>
{/block}

?>