jQuery Animation .toogleclass

Hey, i want to bild a toppanel which will change his height after the user has clicked on the button. But the nice dropdown effect ony appears once. When i am trying to close the panel the effect doesn’t appear. Demo: http://www.color4you.org/demo/domination/ (The box on the right side is the demo button)

 $(function() {
    $( "#tp-button" ).click(function(){
    $("#toppanel").toggleClass("show", 1000, "easeOutSine");
    });
});

My css classes:

.show {

height: 180px!important;

}
#toppanel {
    position: absolute;
    width: 100%;
    top: 0px;
    height: 10px;
    background-color: #cacac7;
    z-index: 999999;
}

<div id="tp-button" />
<div id="toppanel" />

Thanks in advance!

Fixed!