ValkoN,
if (!$user_id) {
echo '<b>Вход</b>
<div align="center">
<form action="/login.php" method="post">Логин:<br/>
<input type="text" name="n" value="" maxlength="20"/><br/>Пароль:<br/>
<input type="password" name="p" maxlength="20"/><br/>
<input type="checkbox" name="mem" value="1" checked="checked"/>Запомнить<br/>
<span class="button-wrapper">
<span class="l"> </span>
<span class="r"> </span>
<input class="button" type="submit" value="Вход"/></span>
</form>
</div>
<div><a href="users/skl.php?continue">Забыли пароль?</a></div>';
}