Constrains dragging to within the bounds of the specified element.
Examples
sample
<style>
.container { border: 1px solid #999; width: 600px; height: 600px; }
.element { border: 1px solid #999; width: 300px; height: 200px; cursor: move; text-align: center; background-color: #DDD; }
</style>
<div id="container" class="container">
<div id="element" class="element">drag me</div>
</div>
<script>
$('#element').draggable({
containment: document.getElementById('container')
});
</script>