Problem with jquery toggle

I have found this piece of code the works for a jquery slide up toggle. This issue I’m having is that when I click for it to slide up it does so but it appears that it’s coming from below the coltab div. I’d appreciate if you could help me with a solution.

<style>
body { margin: 400px 50px; }

#coltab { position: relative; text-align: center;
height:370px;}

#coltab > li {
    background: #ccc;
    color: #444;
    cursor: pointer;
    display: block;
    float: left;
    margin: 0 10px;
    padding: 10px 20px;
    position: relative;
    width:260px;
    height:50px;
}

#coltab span {
    background: #eee;
    color: #222;
    display: none;
    padding: 5px;
    width:290px;
    height:200px;
    position: absolute;
    left: 0;
    right; 0;
    top: 0;
    z-index: -1;
}

#coltab span.open { display: block; }

</style>

<head>

<script type="text/javascript" src="http://jqueryjs.googlecode.com/files/jquery-1.2.6.min.js"> </script>

</head>

<body>



<div id="coltab">
    <li>Item 1<br/>(click me)
            <span>This first item needs to toggle up</span>
    </li>
</div>

<script>
$(document).ready(function() {
$("#coltab li span").each(function (index) {
  $(this).data('height', $(this).outerHeight());
});

$("#coltab li").click(function () {

    $("#coltab li span.open").animate({"top": 0}, function () {
        $(this).removeClass('open');
    });

    var itemHeight = $(this).children('span').data('height');
    $(this).find('span:not(.open)').animate({"top": -itemHeight}).addClass('open');

});
});
</script>
</body>

What exactly do you want it to do? I don’t think you specified the solution you want to get.

the problem I am having is that when I click ‘Item 1’ the toggle slides up, however the slide appears to be coming from uderneath the div called coltab and you can see it sliding from below the div upwards. Is it possible to eliminate this problem by making it slide without this issue.

still stuck with this issue. has anyone any ideas on how I might solve this. thanks