Jquery/css onhover change div(floated) height

http://sedeljka.com/test.html

4x4 floated divs

i want on mouseover to change div height


<style>
.thumbnail {
 width:200px;
 height:200px;
 float:left;
}

.thumb_hover {
 width:200px;
 height:250px;
 float:left;

/* position:absolute; dont work */

}
</style>

<script>
$(document).ready(function(){
	$(".thumbnail").hover(function() {
        id=$(this).attr('id');
        $("#" + id).addClass('thumb_hover');
   			}, function() {
$(".thumbnail").removeClass('thumb_hover');

	});


});
</script>

<div class="thumbnail" id="thb1">
test
</div>
<div class="thumbnail" id="thb2">
test
</div>
....
....



  1. position:relative

  1. position:absolute

i want something like this: