begin,
пример
<!DOCTYPE html>
<html>
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<title>demo</title>
<script src="http://code.jquery.com/jquery-1.9.1.js"></script>
<script src="http://code.jquery.com/ui/1.10.3/jquery-ui.js"></script>
<style type='text/css'>
#constructor{
padding:0px;
width:335px;height:335px ;
background-color: #4169E1;
}
#constructor div{
width:40px;height:40px ;
background-color: #DEB887;
position: absolute;
}
</style>
<script type='text/javascript'>
$(window).load(function () {
var id = 0;
$('#add').click(function ()
{ id++;
$('#constructor').append("<div id='item_" + id + "'>текст</div>");
$('#item_' + id).draggable({containment:'parent',zIndex:id});
})
});
</script>
</head>
<body>
<input name="" type="button" value="добавить блок" id="add">
<div id="constructor" class=""></div>
</body>
</html>