Simplified Version of http://codereview.stackexchange.com/questions/31367/toggle-script-trouble

HTML

<ul>
    <li><a href="#" class="dropdownBtn">show alles</a>
        <ul id="submenu" class="submenu1">
            <li >alles content</li>
             <li>alles content</li>
        </ul>
    </li>
    
</ul>

JavaScript

$('.submenu1').hide();

var topContainer = $("#submenu");
var topButton = $(".dropdownBtn");
topButton.click(function () {
    topContainer.slideToggle(200);
});