<script type="text/javascript">
$(function () {
var tabContainers = $('div.logout > div');
tabContainers.hide().filter(':Login').show();
$('div.logout ul.tabNavigation a').click(function () {
tabContainers.hide();
tabContainers.filter(this.hash).show();
return false;
}).filter(':Login').click();
});
</script>
<div class="logout">
<ul class="tabNavigation">
<li><a class="" href="#Login">Вход</a></li>
<li><a class="" href="#Reg">Регистрация</a></li>
</ul>
<div id="Login">
1
</div>
<div id="Reg">
2
</div>
</div>
filter(':Login')